The Taj Mahal, one of the most celebrated monuments of the world, is not only a masterpiece of Mughal architecture but also a marvel of engineering ingenuity. While its pristine white marble superstructure has been admired for centuries, the architectural brilliance truly begins beneath the surface—with its foundations.
The Taj Mahal’s foundational system showcases a deep understanding of soil mechanics, water management, and stability, far ahead of its time. The choice of site, so close to a major river, posed both opportunities and challenges. To ensure long-term durability and protection from shifting soil and seasonal floods, the Mughal engineers devised an innovative system involving a well foundation technique. Timber, stone, lime mortar, and specially constructed wells were used in a composite structure to support the enormous weight of the mausoleum complex. Hydraulic engineering and traditional knowledge of Indian and Persian construction methods converged in this ambitious foundation, allowing the monument to stand tall and unshaken for over 370 years. This post delves deeper beneath this illuminated white marble tomb.
The History
The Taj, one of the finest tombs in the world, stands on the right bank of river Jamuna and contains the remains of the Emperor Shah Jahan (1627-58) and of his favourite wife, Arjumand Banu Begam, better known as Mumtaz-uz-Zamani or Mumtaz Mahal. She was the daughter of Abu-l-Hasan, entitled Asaf Khan Asaf Jahi, son of I’timad-ud-Daula Mirzi Ghayath, and niece of the illustrious Nur Jahn, wife of the Emperor Jahangir (1605-27). In her twentieth year she was married to Prince Khurram, afterwards the Emperor Shah Jahan, on Friday the 10th May, 1612 A.D. and died on the 28th June, 1631 A.D. after giving birth to her fourteenth child, Princess Gauharara, at Burhanpur in Khandesh (modern day Madhya Pradesh) in the Deccan. Her body was temporarily interred in the garden of Zainabad at Burhanpur, whence, under the orders of Shah Jahan, it was brought to Agra after six months on the 11th December, 1631 A.D. by Prince Shaja, Wazir Khan and Sati-un-Nisa Khanam, sister of the poet-laureate, Mirza Talib Almi (Vats:1946).
In the meantime a suitable site was selected which, being the garden of Raja Jai Singh of Jaipur, was duly exchanged for equally valuable State land, and her remains were again temporarily deposited near the present Baoli in a domed structure on the 8th January, 1632 A.D. until their permanent burial in the mortuary chamber of the Taj. The Emperor himself died on Monday the 1st February, 1666 A.D. and was buried in the same chamber to the west of Mumtaz Mahal’s grave. The question as to who designed the Taj is disputed, but there is epigraphical evidence to show that is was Ustad Ahmad of Lahore. The mausoleum was constructed under the superintendence of Makramat Khan and Mir Abdu-l-Karim, the dome being built by Ismail Khan of Turkey and the inscriptions executed by Abdu-l-Haq, better known as Amanat Khan of Shiraz (Vats:1946). The court historian Mullah Hamid Lahori gives a vivid description of the main and the subsidiary buildings; all the relevant information can be gathered from Badshahnama.
The Architecture
The work of construction of this great monument started from the very foundation in 1631 A.D. and completed in 1648 A.D. with the mosque on the west, the jawab or mihmankhana on the east, and the main gateway on the south. The outer court and its cloisters being added subsequently and completed in 1653 A.D. (Vats:1946). The entire project (wages and miscellaneous expenditure excluding the cost of materials like marble and semi-precious stones) was carried at a total cost of Rs. 50 lakhs. All the relevant information that can be gathered from Badshahnama is, first that foundations were laid by excavating down to the sub-soil water level, second, that masonry below the ground is of stone-in-lime and third that platform above the ground is of brick-in-mortar.
The principal materials used in the core of the tomb proper, its minarets and other accessory buildings is essentially brick (Lakhauri) and lime mortar. The external surface of the tomb building including its dome, drum, minarets, and interior of cenotaph chamber are lined with white marble veneering whereas all the other interior of all the other accessory buildings such as mosque, quest house, gates, etc. had been veneered with red sandstone except the exterior surfaces of domes. Besides in the accessory buildings a coat of red octet was applied over the thin layer of special lime plaster invariably provided on red sandstone surfaces basically for the purpose of proper protection of the stones as well as for the decorations. Further, all the important external and internal surfaces of the monument were embellished with rich variety of highly artistic and delicate inlaid or piertre dura ornamentations. The chief materials used in the inlay work include black marble, yellow marble, varieties of agate and jasper, coral, cornelian, turquoise, Jade, crystal, lapis-lazuli, garnet, onyx, chalcedony, amethyst, sapphire, diamond, etc. These precious and semi-precious stones were imported from different parts of the world where as white marble and red sandstone came from the quarries of Makrana, in District Nagaur of Rajasthan and Fatehpur Sikri in District of Agra of Uttar Pradesh respectively.
The main tomb building measuring 57.30 meter in width as well as height above the plinth level and identical in elevation of all four sides is located on a square platform of side 95.65 meter. The plinth itself rises about 6 meter above the ground level. The predominant feature of the structure is its 23 meter high dome from the springing to the base of 9.8 meter high gilded finial or pinnacle resting on a cylindrical drum of 18.4 meter internal diameter and rising 12 meter above the terrace roof. The drum is supported by eight octagonally arranged piers interconnected with arches. The octagonal main hall or cenotaph chamber thus created below the double dome measures 17.74 X 17.74 meter in plan. This central hall is surrounded by four octagonal corner chambers measuring chambers measuring 8 X 8 meter and four square chamber of side 4.8 meter. These surrounding chambers also exist on the floor above and are interconnected by vaults at both the levels. In addition four minarets measuring about 5.8 meter in diameter at the base and 41 meter in height are located at the four corners of the plinth platform.
The Foundation of the Taj Mahal
Owing to the proximity to the river Yamuna, the whole fabric together with the four corner minars has been made to rest on a firm bed of masonry which seems to have been supported on piers sunk at close intervals in accordance with the Mughal practices (Vats:1946).
The earliest record of its repairs is available in a letter, dated 1652 A.D., from Prince Aurangzeb to his imperial father, Shah Jahan, wherein he points out defects in the dome and vaults of the mausoleum, saying, the do me of the holy tomb leaked in two places towards the north during the rainy season and so also the fair semi-domed arches, many of the galleries on the second storey, the four smaller domes, the four northern compartments and the seven arched underground chambers, which have developed cracks. History is, however, silent about the actual steps taken by the Emperor on the Prince’s letter in respect of repairs to the dome (Flynn: 1974).
Other References regarding materials used and construction method of the foundation
- No architectural drawings of Taj Mahal are preserved. The only evidence is a few incised patterns on stone slabs re-used in buildings. There is very little written evidence about the actual construction of the Taj Mahal. From accounts of the building of the Red Fort at Delhi, slightly later; we learn that the head of the architects, with his assistants, would first chalk out the plan on the ground. Diggers (beldar) would then excavate the foundations (Koch: 2006).
- Koch,E. 2006. The Complete Taj Mahal and the Riverfront Gardens of Agra. Thames & Hudson Ltd (London), pg. 96.
- Bhatnagar, V.S., 1974. Life and Times of Sawai Jai Singh,1688-1743 (Delhi), pg. 331.
- Singh, C. 1986. ‘Early 18th-Century Painted City Maps on Cloth’, in Facets of Indian Art (London), pg 190-192.
- Sachdev, V., and G. Tillotson, 2002. Building Jaipur, The Making of an Indian City (London/New Delhi).
- Kalim Kashani, also known as Abu Talib Kalim, was a prominent Persian poet who served as Shah Jahan’s court poet and authored works, including an epic poem also titled “Padshahnama” detailing Shah Jahan’s accomplishments. According to Kalim, in a verse he says that it was difficult to lay down the foundations in sand, where there is river; this was done by means of wells encased in wood and filled with rubble and iron. Kalim’s description was supported in the 1905s when excavation of the foundations revealed wells filled with rubble, placed at a distance centre-to-centre of 3.76 m (11½ ft). Foundation wells of this type can be seen exposed in the riverbed in front of several of the gardens on the left bank of the Yamuna- the garden of Jahanara/Zohara Bagh, the Chini-ka Rauza, and the garden of Khwaja Muhammad Zakarya or Wazir Khan. The foundations of Taj proved so stable that they did not give way during the great floods of September, 1978, when the river level almost reached the top of the platform of the mausoleum (Koch: 2006).
- Koch, E. 2006. The Complete Taj Mahal and the Riverfront Gardens of Agra. Thames & Hudson Ltd, London, pg. 96.
- Abu Talib Kalim Kashani, Masnavi-e-Padshahnama
- Titley, N. M. Miniatures from Persian Manuscripts: Catalogue and Subject Index of Paintings in the British Library and the British Museum (London 1977), pg. 117, no. 253
- Lalah Silchand, 1825-26. Tafrih al – imarat, an account of the public buildings of Agra, composed for J.S. Lushington, acting collector and magistrate of Agra. No. f. 67 Taj Mahal Gate and f.73 Taj Mahal.
- Lahauri tells us that the foundations were ‘built of stone (sang) and [watertight] mortar or cement (saruj)’, and that on them a terrace (chabutra) of brick (ajir) and mortar (ahak) was built, on which the main buildings were placed. Its exterior (ru-yi kar), especially the front to the river, was artistically faced with red sandstone (Archer: 1972).
- Archer, M, 1972. Company Drawings in the India Office Library, (London), pg. 192, no. 157 i-v.
- Section of the entire complex, from the riverfront at the north (left) to the south (right), with the east gate and ranges of the bazaar and caravanserai complex partly reconstructed. This, the first section ever prepared, shows how the complex falls in terraced steps towards the river (Koch: 2006).
- Foundation wells below and beside the river frontage of the Taj Mahal [cf. 206].
- Foundation wells similar to those that underly the riverfront terrace (cf. 124) are seen here in 1958, after they had been exposed by excavation. They supported steps leading down to the river below the mosque and the north-west tower. Steps and foundations are now invisible.
- The drain running along the foot of the wall on the riverside was opened to ascertain the cause of the cracks and the percolation of water in the underground vaults on the river-front. No cracks were noticed in the stone bed of the drain, but the chequered stone pavement alongside had longitudinal cracks, through which water apparently percolated. The cracks, one of them running to a length of 207 ft., were thoroughly grouted with cement and hydraulic lime. Trial-pits dug along the outer wall on the riverside to find out the foundation-strata exposed a series of wells used as foundation (pl. CII).
- To find out the foundation-strata on the river-side, a trial-pit, about 50 ft. long, had been previously dug (1957-58, p. 83) and two wells exposed. It appears that the structure had been raised on well-foundations with filings of rubble-masonry in between (pl. XCII A). The centre-to-centre distance of the two wells was 11 ½ ft.
- In order to counteract the scouring of the foundation by the river during floods, rubble pitching encased with galvanized-iron wire-netting to a length of about 70 meters was done along the plinth of the north wall near the north-west tower (pl. CIII).
- The site on which the Taj presently stands marks a point where the Jamuna takes a sharp curve with the least thrust of water and accurately faces the east. It thus fulfilled all the three requirements and was consequently selected.
The architect was fully conversant with his materials and knew well how to use them to the best advantage…… The cementing agent which had thus been prepared was very strong and enduring. The brick was reduced from the standard Mughal size of 8″ x 7 ½” x 1 ¾” to 7″ x 4 ½” x 1″ so that the vajra mortar could occupy a greater cubic volume of the construction than that which could be filled with the brick. Perfectly baked bricks of first class quality were selected. They were fed into hot fat, mixed with some chemicals, which were absorbed into the porous body of the brick. This thin, almost imperceptible, overcoat made the bricks adequately water-proof.
The sepulchre was built at the edge of stylobate which originally sloped into the river (Fig. 35). A study of the river bank downstream as far as the Lal Mahal confirms this contention. Very deep foundations were dug which extended right down to rock level. As was the Mughal custom, the system of well foundation was adopted on a very refined scale. The plans and sectional diagrams, which are no longer available, must have been prepared beforehand with the utmost care, localizing the load and the distribution of the weight on the massive piers. The foundations were raised in accordance with the superstructure so that each massive pier could rest on one series of wells which were connected together by means of strong arches. Each well is composed of a massive circular wall of kakai bricks and lime mortar of great strength with axles and spokes placed in it at regular intervals along the whole depth.
The core was filled with rubble mixed with mortar. The space between the wells was filled with solid masonry composed of stones and lime. The load was evenly distributed and passed down to the foundations without the slightest apprehension of lateral thrusts. Thus, every care irrespective of cost was taken to provide the huge mass above with a firm and compact base, which originally rose to a height of 16 Shahjahanian yards, equivalent to 43 feet (13.11 meters) from the Jamuna level. While each massive pier carrying the huge load above it rested directly on a series of wells, the whole was so bonded together as to make it a perfectly compact body. The well-foundation had its advantages near the water in as much as it minimized the danger from displacement of soil, uneven distribution of the weight, and unequal settle-
To counteract the inevitable thrust of water, wells were also piled towards the riverside outside the foundations at close intervals. The wells are in series of three, seven and seventeen and concentrate in large numbers near the north-west corner of the building, i.e., the Basai Burj where the apprehension of the dangerous thrust of water was the greatest. They bave also been distributed, though sparsely, along the whole northern side of the building. Each such external well is also composed of a massive circular wall of kakai bricks and strong lime mortar with wooden (Deodar) axles and spokes. The core is filled with mud and sand. This well-foundation is a typical feature of Mughal architecture, used almost invariably in all buildings constructed on the river bank, e.g., at Rambagh, Chini-ka-Rauza, the tomb of Itmad-ud-Daulah and others. The greatest advantage of this expedient on the external side is that it faces and neutralizes the thrust of water before the latter can do any harm to the building: it counteracts the thrust almost like a living organ as it remains afloat intact, even when it is dislodged at its base. Overlaid with mud and sand which the river deposited every year these wells provided an invincible shield to the building.
The walls of the cenotaph hall carry a heavy load at 7.9 tons (8.02 metric tons) per sq. foot, almost twice the safe limit of 4 tons (4.06 metric tons) of the strongest construction of modern architecture! The architect of the Taj might not have calculated the weight so accurately as he was not a theoretician. But as a practical expert in his art he had all these details in constant view and uniformly distributed the load throughout according to the principle which is known as the ‘Cone of Incidence’ in modern architecture. The load is not allowed to concentrate at any one point or to rest unevenly.
Extraordinarily massive piers and vaults were constructed to support this heavy load and to pass it down safely to the solid pile foundations. An efficient system of headers and stretchers, reinforced with iron clamps, was resorted to, to withstand the bursting effect of the heavy load. With the very best quality of the bonding material the architect successfully combated the disruptive tensile stress. A very judicious use of the arcuate system has been made to span the spaces in conformity with the plan of the sepulchre, while all the time the aesthetic considerations were kept constantly
It is not known how in spite of all these precautions and care, dangerous cracks and leakages developed in the substructure just four years after its completion. Aurangzeb in his letter to Shah Jehan in A.D. 1652 mentions these cracks which he noticed in the seven arched underground vaults.
- Nath, R. 1972. The Immortal Taj Mahal:the evolution of the tomb in Mughal architecture. Publication D. B. Taraporevala Sons (Bombay), pg. 79-80.
- “The Taj in Danger”, in the Sunday Standard, April 7th, 1968.
- Final Report of the Advisory Committee on the Restoration and Conservation of the Taj 1942 (Delhi), pg. 7, 8, 18, 26, 27, 105, 813.
- Flynn, V.J.A. 1974. An English Translation of the Adab-i- Alamgiri, thesis submitted at The Australian National University (Australia), pg. 29
- A study on foundation and stability of Taj Mahal. The conclusion highlights that for the first time, it has been possible to establish fairly conclusively the subsoil stratification beneath the 350 years old Taj Mahal and assess the performance of foundation of the structure with the help of a large number of field and laboratory test data. The proposed impounding of water in the river Yamuna upto RL 146.0 m will have no influence on the behavior of subsoil strata and hence on the performance of the foundations of Taj Mahal. The future settlement of the foundation is likely to be insignificant and will present no problem to the stability of Taj Mahal.
The Riverfront Terrace (Chabutara /Kursi)
The terrace of the Taj Mahal is the most ambitious ever built in a Mughal riverfront garden scheme, unprecedented in size and decoration, and one of the most impressive platforms in the history of architecture. From the landward side it is hardly noticeable: since the site slopes down towards the river ( fig.145), the terrace rises only 1.22 m (4 ft) above the level of the garden – just high enough to announce itself (fig.205). Its full splendor is displayed towards the river, where it forms an uninterrupted red sandstone band 8.7 m (28 ft 6 in.) high from the lowest visible plinth and 300 m (984 ft) long, with elaborate decoration in relief and inlay work (Koch: 2006).
- Construction of the Taj Mahal started with the foundations of the riverfront terrace. After that, work seems to have gone on simultaneously over the entire complex.
- The riverfront terrace was the first part of the Taj Mahal complex to be built (pg. 97). Lahauri described it thus:
“And on top of the foundation the platform (kursi) of the exalted mausoleum, which imitates the gardens of Rizwan [the guardian of Paradise] and gives an impression (nishan) of the holy abodes, was raised like a terrace (chabutra asa) of brick and mortar in one solid block…. and in the centre of this terrace of the rank of the Throne of God (kursi-yi arsh martaba) was raised another solid platform (kursi)…. faced with white marble.,”
- Koch, E. 2006. The Complete Taj Mahal and the Riverfront Gardens of Agra. Thames & Hudson Ltd, London, pg. 144.
- Koch, E. 2006. The Complete Taj Mahal and the Riverfront Gardens of Agra. Thames & Hudson Ltd, London, pg. 145, fig. 206 right.
- Koch, E. 2006. The Complete Taj Mahal and the Riverfront Gardens of Agra. Thames & Hudson Ltd, London, pg. 145, fig. 205 opposite.
- Taylor, Bayard, 1855. A Visit to India, China and Japan (New York), pg. 131
- Lahauri uses the word kursi for the terrace, for the platform on which the mausoleum stands, and for its low plinth, treating all three semantically on equal terms. Kursi also means throne, and this leads to the comparison of the terrace with the ultimate throne, the Throne of God. The importance of the terrace is expressed in its linguistic treatment, in its grand form, and in its elaborate decoration.
- Below the terrace there were landings in the form of wide flights of steps (ghats), which are now covered with sand and silt but which are visible in photographs of the 195os when part of the front foundations were excavated (fig. 206).
- The terrace is paved with geometrical patterns – of lighter and darker sandstone slabs, and, around the mausoleum, of sandstone and marble. The gallery inside the terrace is not mentioned in official descriptions, but Aurangzeb refers to it in his report of 1652 as tahkhana-i kursi haftadar, ‘the terrace tahkhana of seven arches’.
- Koch, E. 2006. The Complete Taj Mahal and the Riverfront Gardens of Agra. Thames & Hudson Ltd, London, pg. 147.
- Flynn, V.J.A. 1974. An English Translation of the Adab-i- Alamgiri, thesis submitted at The Australian National University (Australia), 29
Conclusion
Thus, the foundations of the Taj Mahal stand as a silent testament to the genius of Mughal engineers and architects, who seamlessly blended aesthetics with structural innovation. While much attention is rightly given to the Taj’s artistic splendor above ground, its enduring legacy owes just as much to the brilliance hidden below. Far beneath the gleaming marble domes and minarets lies a complex network of wells, stone/brick plinths, and hydraulic strategies that have safeguarded this iconic monument against the tests of time, weather, and terrain.
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