There is no dearth of scholarly revelations regarding this topic. C. Mani’s edited book (2008).‘The Heritage of Nalanda’, explains how Nalanda emerged from a monastic institution into the greatest academic and spiritual centre in the Asian continent in the early medieval period. The book stands as a good contribution to the field of Buddhist studies and is valuable for a general interest among the readers as well as academicians. ‘The Last Disciple of Nalanda’(2015) written by Suresh Nair is an account of a disciple of the university named Ermen who belonged to the Oirat tribe of the Russian Mongol steppes in late twelfth century. He was very famous for his erudite answers to the questions thrown to him by the gate-keeper of the University. The book also contains the event of his establishing some roving monasteries and his efforts for preaching and practising Buddhism. Sahana Singh’s book ‘The Educational Heritage of Ancient India’ (2017) describes the status of Nalanda University as a multi-disciplinary centre of learning and its contribution to ignite the knowledge revolution around the world. It has given a little space for the history of Muslim invasion over this monumental university. Shivani Singh’s ‘Nalanda’ (2021) explains the royal investigation of a suspicious death in the campus of Nalanda University, where a young Buddhist monk named Siddhartha, is asked to aid the investigation during the period of Mahipala, the king of Magadha. Despite the presence of such books, several other articles and writings, we lack a comprehensive account responsible for the decay and decline of the Nalanda University and this article is a very genuine effort in that direction.

Nalanda was a Buddhist foundation and its central focus consisted of the studies of Buddhist philosophy and practice. The nature of the philosophy of Buddha was a basic epistemic and ethical curiosity in the tradition of intellectual Buddhism that sought knowledge in many different fields. The main hypothesis of the paper is to recollect the pursuit of science in ancient Nalanda which will inspire and guide the government’s long run efforts in new Nalanda. Secondly, Nalanda is the only non-Chinese institution in which any Chinese scholar was educated in the history of ancient China. The paper further speculates that the same situation would arise in India particularly in newly established Nalanda University where the Chinese scholar would be educated in the history of ancient China.

The following pages describe the destruction of educational institutions as well as cultural centres in the Asian continent either deliberately, accidentally or by a natural disaster. To be noted here that the deliberate and systematic destruction of educational and cultural places is regarded as a form of cultural genocide.
China
Historical Famen Temple witnessed demolition and destruction on several occasions. Erected first during the Eastern Han dynasty (25 A.D. - 220 A.D.), it was first destroyed during the years of the Northern Zhou dynasty (557 A.D.-581 A.D.). The An Lushan Rebellion (755 A.D.-763A.D.), which lasted for around seven years, devastated the city of Chang’an, a historical capital of several ancient Chinese empires. The city was sacked and occupied several times by the rebels who looted and demolished the buildings, whose materials were reused to build the subsequent capital city of Luoyang. During the systematic persecution of Buddhists in 845 A.D. by the Taoist emperor Wuzong of Tang, more than 4,600 Buddhist temples were destroyed empire wide. In 955 A.D., Emperor Shizong of the later Zhou ordered the systematic destruction of Buddha statues due to the need of the copper to mint coins. The ordinance led to the destruction of 3,336 of China’s 6,030 Buddhist temples.
Syria
The Royal Library of Antioch was established  by Antiochus, the Great of the Seleucid Empire around 221 B.C.in ancient Syria and opened it to the scholars. The Roman (Christian) emperor, Jovian destroyed the Royal Library of Antioch and burnt the books which sufficed enough to annoy the citizens of the city.
India- Nalanda University
Nalanda is one of the most famous places in the history of Buddhism as the greatest seat of learning of the medieval times. The early canonical texts of both the Jains and Buddhists refer to it as a ‘suburb’ or as a hamlet or village situated in the outskirts of ancient Rajagriha (or modern Rajgir). The Pali texts of Buddhist contain numerous references to it under the various names of Nala, Nalaka, Nalakagrama, Nalanda and generally take it to be the birth place of Sariputra, one of the most famous disciples of the Buddha. It is, however, curios that the place, under the namesakes of Nalanda, is not to be found mentioned in early Hindu literary works, such as the epics and the Puranas; though Rajgir figures quite often in the Mahabharata. The historians opine that Nalnda was most probably established in the mid-5th century A.D. by  Kumargupta I ( 415 A.D.-455 A.D). Harshavardhana of the Pushyabhuti dynasty of Kanauj (606 A.D.-647 A.D.) was perhaps the most benevolent of all the royal patrons of Nalanda.[2] From the eight to twelfth centuries, the Pala emperors ruled over Bihar and Bengal as most of them were devout Buddhists, Nalanda continued to receive the benefits of royal patronage for a considerable length of time to come. Of these Pala rulers, Devapala (9th century), Gopala II and Mahipala I, figure more prominently as patrons of Nalanda. The reign of Devapala was particularly eventful for the institutions of Nalandawhich now attracted royal patronage from a king even of the far off countries like Suvaranadvipa and Yavadvipa  (i.e. Sumatra and Java respectively), who himself built a monastery here and made a liberal endowment of five villages for its future maintenance and preservation. His interest in the Nalanda monastery and deep devotion to the Buddhist faith are also known from the Ghoshrawa inscription (No.8). It records that Indragupta, a Brahman of Nagarahara (Jelalabad) and a learned Buddhist priest, received ovation from Devapala and was appointed the head of the Nalanda monastery.[3]
The ruins of the ancient Buddhist establishments of Nalanda lie close to the village of  Bargaon, about 55 miles of south-east of Patna and seven miles north of Rajgir, the ancient Rajagriha. The ruins are situated at a distance of about two miles from the Nalanda station on the Bukhtiarpur-Bihar Light Railway.4 Excavations have shown that Nalanda university covered an area at least one mile long and half a mile broad. The university offered free lodging and boarding to its lay students- who were usually Hindus- in view of its having received so many endowments from Hindu patrons. When I-tsing was living at Nalanda (675 A.D.), there were more than 3,000 monks residing in the establishment. The biographer of Yuan Chwang states that in the second quarter of the seventh century, the number of the residents of Nalanda would always reach 10,000. Nalanda, however, was not a mere monastery; it had obtained so wide a fame primarily because it was a very famous center of learning. There was a great rush for admission to the Nalanda University. Students from all parts of India and also from distant foreign countries like China, Korea, Tibet and Tokhara were anxious to get the benefit of its instructions.  The university maintained a splendid library to meet the needs of the hundreds of teachers and thousands of students that were engaged in the study of different sciences. Significantly enough, the library quarter was known as Dharma-ganja, Mart of Religion. It was located in three splendid buildings appropriately called Ratna-sagara, Ratnodadhi and Ratnaranjaka. The curriculum at Nalanda was very comprehensive and catholic. The establishment belonged to the Mahayana school of Buddhism, but the works of the rival school, the Hinayana one, were also taught. At the head of the general administration was the abbot-principal, who used to be assisted by two councils, one academic and the other administrative.[5] When Hiuen Tsang arrived at Nalandain 637 A.D., Silabhadra was the chief of the monastery. Silbhadra mastered the principles of Buddhism and attained high efficacy in explaining the subtleties of the Shastras.[6] Nalanda was a repository of learning for the central India, a centre from which learning spread over the whole of the country. Medicine appears to have made great progress in the Buddhist age, when hospitals were established over the country. But it was in Astronomy that the most brilliant results were achieved in the Buddhist age.[7]

Causes of Decay
Several causes have contributed to the decay of the Nalanda University. Its buildings must have become old and dilapidated owing to the lapse of ages and secondly, it must have been cast into the shade by the growing splendors of the rival university of Vikramsila to which the attention of the kings was directed and which necessarily led to the withdrawal of royal patronage.[8] The third and most destructive attack came when the university was destroyed by the Muslim army led by the Turkish leader,Bakhtiyar Khilji in 1193.
Let us discuss the age related problems for its decay. Since stone was not readily available at Nalanda, the most common building materials used are bricks for the walls as found in almost all the buildings. Stone ruins are scarcely to be seen except in the loose stone images and bases of pillars used obviously for constructional reasons. It is further observed that for the pillars in the verandahs of almost all the monasteries and for the roofs of most of them, wood was the material used. Traces of chulhas in the verandahs of some of the monasteries are also noticed. Ovens in the open courtyard are also visible. It has been suggested that cooking was done inside the monasteries which involved storage of fuel, consisting obviously of wood and other combustible material, within the premises, as is commonly seen in Indian villages. The monks may have also used naked lamps, if not torches, during nights. Accidental fires in such circumstances are quite common in India even now in the countryside. It is, therefore, most likely that the damages were more common and frequent from such accidental fires and it is quite probable that, because of this pasty experience, the builders used stone pillars in the later monastery. While excavating the sites, the excavators are frequently seen commenting that the particular monastery was probably destroyed by fire; but they do no state the probable causes of such fires.[9]
The second possible reason for its decay was the establishment of the new University of Vikramshila (Bhagalpur) by Pala king, Dharmapala (783 A.D to 820 A.D.). Atisha, the renowned scholar is sometimes listed as a notable abbot. From the 11th century onwards, the new university of Vikramshila began to receive a greater share of the royal patronage. Taranath informs us that the professors of Vikramshila were often appointed to watch over the affairs of Nalanda by the Pala rulers.[10] These circumstances may have led to the decline of Nalanda during the 11th and 12th centuries. Evidence from the Tibetan sources shows that by this time, Tantracism had acquired a hold over the Buddhist mind and it may have perhaps affected the progress of serious studies. But, we, have, no definite evidence on the point.[11]
The third possible cause of the decay of the Nalanda University was the Muslim raids. It was destroyed by the forces of Muhammad bin BakhtiyarKhilji around 1193 CE.[12] The buildings were burnt or destroyed and the whole of the monk population was put to the sword. Bakhtiyar Khiji was in the service of a commander in Awadh who wanted to make a name for himself. He was assigned two villages on the border of Bihar which had become a political no man’s land. Encouraged by the support of his superiors, Bakhtiyar decided to attack a fort in Bihar and was able to successfully capture it, looting it of a great booty. Minhaj-i-Siraj wrote of this attack:
“ Fearless Muhammad-i-Bakht-yar not only captured the fortress but also acquired great booty. He also damaged a great number of books and killed the Brahmans present there. On becoming acquainted with the content of those books, it was found that the whole of that fortress and city was a college, and in the Hindi tongue, they call a college Bihar (Vihara)”.[13]
While many historians believe that this monastery which was mistaken for a fort was Odantpura, some are of the opinion that it was Nalanda itself. Nevertheless, both became the victims of demolition and destruction. It is, however, most striking that no Muhammedan Makhdum, Pir or saint of great repute happened to grace the tops of the Nalanda mounds with their tombs or mosques. This is a feature, which, it should be noted, is commonly to be observed all over Bihar at sites of celebrated and important living sanctuaries, which had invariably attracted the attention of the Musalman invaders for the erection of such monuments. Though we can see some Muslim monuments at Bihar Sharif even today,  but its absence at Nalanda at a  very short distance surprises us.  Again, had Nalanda been a living institution of great repute or importance at the time of the invasion of Bakhtiyar Khilji, we should expect the Muslim Chronicles of the event to have known and mentioned the name of Nalanda. As is known, one of the Pala rulers had established a monastery at Odantapuri or Bihar Sharif itself which may have affected adversely the fortunes of Nalanda. All these circumstances would indicate that, quite before Bakhtiyar Khilji’s invasion, Nalanda had perhaps fallen to decay or ruins already; but how and when actually this happened is still a mystery to be unravelled.[14]

The accounts of Chinese and Indian scholars firmly confirm that an aspect of the intellectual and rational life had emerged powerfully at the Nalanda University. So, the demand of the day is that the rational culture in Indian intellectual history must be pushed forward. Again, the Nalanda University stood for the passion of propagating knowledge and understanding. Modern day educational institutions in India should pursue the same path to spread enlightenment among people of all lands.