"The convents are numerous, but mostly deserted and ruined. Of those preserved there are about 20, with 1,000 or so priests. They all study the law of the Great vehicle. There are a 100 Deva (Hindu) temples, and the people who frequent them are numerous and of different beliefs."
Though what he says about Amaravathi itself is disappointingly meagre it establishes the fact that Buddhism was an important state religion in the Andhra kingdom.
Growth of Buddhism in Andhra
Buddhism came to Assaka country (today's Nizamabad in Andhra Pradesh) during the Buddha's lifetime. Bavari, an ascetic who set up his ashram on the banks of the Godavari river, came to know that a Buddha had arisen in the north and sent his disciples to meet him and engage him in a spiritual dialogue.
The dialogue of the Buddha with the disciples of Bavari at Vaishali is recorded in Suttanipata, which says that Bavari's disciples were converted to Buddhism and later brought dhamma to the Telugu country, Andhradesa. Literary, epigraphical and archaeological accounts confirm that almost all schools of Buddhism flourished in Andhra Pradesh for over 2,000 years. According to Suttanipata, identified as one of the older parts of Tripitaka (the complete scripture collection of the Theravada school).Even though the traditional accounts of the Buddha's visit to Andhra Pradesh are discounted, the literary evidence, as recorded by the Chinese traveller Hiuen-Tsang, shows that Buddhism entered Andhradesa by circa 400 B.C.
It was only during the reign of Asoka that the Buddhist establishment at Dhanyakataka (today's Dharanikota) attained great recognition. Asoka raised the dhamma thambani and enlarged the stupa, enshrining in it the relics of the Buddha and providing the granite railing. The historian B.S.L. Hanumantha Rao said: "Asoka bestowed special attention on Andhradesa as he found out the preference of Andhras for Buddhism."
Being an urban centre with access to the Bay of Bengal coast, Dhanyakataka grew as the focal point of Buddhism in Andhradesa. Its importance grew further when it became the capital of the Satavahanas. The Satavahana expansion over coastal Andhra and the shift of the capital to Dhanyakataka was a notable change in the first century A.D. As a result, the Andhra coastline became the hub of trade with the Romans. These changes fostered prosperity, and Buddhist establishments came up with the support of local chieftains along the trade routes in the hinterland.
The monuments built by the Satavahanas were primarily Buddhist. They were stupas (tombs erected by Buddhists over the remains of the Buddha), viharas (places where Buddhist monks lived) and chaityas (combination of a stupa and a vihara and also a place of worship).
Vajrayana, the third major school of Indian Buddhism, with its manifestations born out of Mahayana, was practised at Dharanikota. According to L.M. Joshi, Andhradesa was an ancient and popular home of Vajrayana. Dhanyakataka was the centre of Vajrayana where the Kalachakra system was expounded by the Buddha.
The foundations of the stupas in the State looked like radiating and concentric brick walls, which are absent in stupas of northern India.
The stupa was a symbol of the Buddha's death. Umbrellas were sometimes mounted at the top of stupas as a sign of honour and respect. There were four gateways in the railing around the Stupa. Each one of the gateways marked one of the four directions, north, south, east and west. The Ayaka pillars found at the four cardinal points and close to the stupas are a peculiar feature of the stupas of Amaravati, which is not seen in the stupas of Sanchi.
The Great stupa or mahachaitya at Amaravathi was one of the biggest in Andhra Pradesh with a probable diameter of 50 meters and a height of 27 meters. It has a brick circular vedika or drum with projecting rectangular ayaka platforms in the four cordinal directions measuring 7.20 X 2.10 meters. Each ayaka pillar must have stood on each platform symbolically representing the five main events in Buddha's life:
The birth
The great renunciation
The enlightnment
The first sermon
Final extinction
The drum and ayaka platforms were covered with sculptured slabs. Five crystal relic caskets containing bone pieces, pearls and gold flowers were discovered from the southern ayaka platform. This is a sariraka type of stupa.
Some of the text in the following paragraph has been borrowed from "The Development of Buddhist Art in South India" By Devaprasad Ghosh -- The Indian Historical Quarterly Vol 4:4, December, 1928, p 724-740
The circular base of the stupa was 162 ft. in diameter, perhaps only 6 ft. high, supporting a frieze and cornice, and was faced with marble slabs possessing the richest carvings and characterised by the most delicate treatments, depicting miniature representations of the stupa itself and interposed by panels elaborately carved with scenes from the life of Buddha and the Jatakas. It is very difficult to ascertain whether the dome rose directly from the drum or rested upon several receding terraces like the Gandhara, Further Indian or Indonesian specimens. The great marble dome of Amaravati, unlike the short and stunted dome of Sanchi, rose to a considerable height of 90ft. (twice that of Sanchi ) and was more or less bulging in form.
Around the outer limits of the Stupa was a tall railing made of limestone. The railing marked the boundaries of the Stupa.
The Tibetan historian Taranatha records that the great Buddhist Acarya Nagarjuna, the founder of the Madhyamika School 'surrounded the great shrine of Dhanyakataka with a railing. Along the top of the railing were limestone blocks carved with reliefs. Blocks placed like this are known as coping. Pillars were carved from large single slabs of stone. Each pillar was about 2.6 metres high and 0.85 metres wide.
Colonel Mackenzie in 1797 was responsible for starting the theory that the stupa was surrounded by two rails--one inner and another outer. It was acknowledged and the mistake was rectified. 'From some misunderstanding of the first accounts' he added, 'it was supposed that the Amaravati Stupa had an inner rail; this was a mistake; the inner circle of sculptures was the facing of the base of the stupa'. The rail at Amaravati resembled its predecessors in the principal features; but the plinth was richly carved with a frieze of running boys and animals, grotesquely treated. The rectangular pillars were as usual edged off into shallow flutes. They were decorated with half lotus discs at the top and the bottom, and circular discs in the middle inserted with a full-grown lotus or a scene, in the usual manner. But the most typical characteristic about these pillars, is the complete absence of the large standing human representations, occupying the entire surface of the uprights, such as the graceful statues of Yaksas and Yaksinis of Bharhut, Bodh Gaya and the dancing girls of Mathura. They have entirely disappeared and their place is occupied by greatly magnified and richly carved lotus discs, curling leaves carefully corrugated, comical Ganas and an enormous variety of scenic sculptures. The preference for group composition, as opposed to single figures, is very obvious in the swarming of the space between the discs--which was generally left bare and unadorned in the earlier days by vivid and animated delineation of the Jatakas and other incidents. The three cross-bars were each embellished with a beautiful lotus disc with concentric bands of petals, the most elaborate of its kind ever made, and all different. On the massive coping, the meandering creeper of Bharhut was replaced by a long wavy roll, carried by moving human figures and dwarfs and interspersed with symbols in the loops. On the whole the inner side of the rail, covered with scenes full of life and movement, was decorated with greater beauty and elaboration than the exterior.
Between the railing pillars were carved stone bars known as 'cross bars'. Each cross bar had a round sculpted face. The round face is all that survives of many of the cross bars.
This cross bar shows a lotus. The lotus is a very important symbol representing purity and goodness in a polluted environment.
The lotus plant usually grows in the murky water of swamps and pools. Its sturdy stem grows up out of the water to support a pure, often white flower which blooms above the water.
The pillar of fire is thought to be the centre of the universe which stretches between Earth and Heaven. This scene on the crossbar shows worshippers around a pillar of fire which represents the Buddha. 
The casing slabs of stupas are decorated with sculptures. The female figures shown are slim and curvy. There is movement, dynamism and pulsating life in both the female and male figures.
Lions represented power and strength and were meant to ward off evil spirits and protect the Stupa. Sculptures of lions were found at the Amaravati site and are thought to have graced the four gateways.
Some slabs invariably present us with another peculiar feature, viz., a dwarf figure standing on each side of the gate, holding a tray on his head. Their constant occurrences lead us to believe that in the original structure they represented statues in the round, bearing trays to receive the offerings of the visitors. Dr. Burgess opines, 'No example of them has been found and the only analogue I know of, is a similar small figure bearing a basin by the doorjamb of the cave at Lonad of the Thana district near Kalyan." But we think a closer examination of the extant monuments may yet reveal such figures and in fact there are such at Karli and in Orissa. A pair of vases with flowers (mangalakalasa?) prominently placed at the entrance is another regular feature of the sculptured slabs.
This relief (the picture on the right) shows a stupa with an empty throne and a dharmachakra in the doorway surrounded by worshippers. This is a symbol of the Buddha's First Sermon. Scenes like this help us to imagine what the Amaravati Stupa may have once looked like.
Decline of Buddhism in Andhra post Ikshvaku period
Royal support, especially by Ikshvaku princesses contributed to the vibrant Buddhist activity at Vijayapuri. During the post-Ikshvaku period, from the fourth century A.D., factors such as the rise of Vishnukundi power to the north of Krishna river and the Pallavas in the southern region and in the north coastal tracts, the resurgence of the Brahmanical religion, lack of royal support and the decline of Indo-Roman trade contributed to the stagnation of the Buddhist centres.
There is evidence that the Amaravati Stupa was still used by worshippers up until certainly A.D. 1344. Hinduism was the main religion in the country at this time, but there were still practising Buddhists in India. Soon after this period, the Amaravati Stupa fell into disrepair.
By the end of the 1700s all that could be seen of the structure was a mound of rubble and some pieces of sculpture on the ground. In 1797, a British colonel named Colin Mackenzie heard of Amaravati and visited the site.
Some of the text in the following paragraph has been borrowed from "The Development of Buddhist Art in South India" By Devaprasad Ghosh -- The Indian Historical Quarterly Vol 4:4, December, 1928, p 724-740
Mackenzie found to his great chagrin that just a year before, the local Raja Venkatadri Naidu had discovered and disemboweled the mound in a fruitless search after hidden treasures; he afterwards caused a reservoir to be dug in the centre and used the priceless marble slabs in building the new temple of Amaresvara and the flight of steps to the adjacent tank of Sivaganga. Some of the slabs were utilised by the Mussalmans in their mosques, after 'carefully divesting of every carving by rubbing them on harder stones, to prevent, as it is said, any pollution arising to Muhammadan faith from idolatrous substances'.
Mackenzie returned to Amaravati in 1816 to find that many pieces of the sculpture had been carted away and reused in local building projects. Mackenzie began to draw and record the sculptures remaining at the site. He recovered some 130 slabs, made drawings of them and prepared a ground-plan of the stupa. To learn more about the sculptures he excavated, visit website: http://www.bl.uk/onlinegallery/features/amaravati/homepage.html. He sent some of the sculptures to the museum at Calcutta.
In 1845, Sir Walter Elliot began excavating at the site. but in the meantime 70pieces of sculptures left behind in the open had been carried away by the enterprising villagers and burnt into lime! It is deplorable that even the Government Public Works Engineers were equally guilty of such acts of vandalism. The slabs excavated by Sir Walter were transhipped to England and now adorn the grand stair-case of the British Museum.
The sculptures which are now in India after surviving the ruthless vandalism through the ages are shared by the Museums of Madras and Calcutta.
