 
Many adherents of Buddhism have experienced religious persecution because of their adherence to the Buddhist practice, including unwarranted arrests, imprisonment, beating, torture, and/or execution. The term also may be used in reference to the confiscation or destruction of property, temples, monasteries, centers of learning, meditation centers, historical sites, or the incitement of hatred towards Buddhists.
Pre-modern persecutions of Buddhism.
Sassanids.
In 224 CE Zoroastrianism was made the official religion of Persia, and other religions were not tolerated, thus halting the spread of Buddhism westwards. In the 3rd century the Sassanids overran the Bactrian region, overthrowing Kushan rule, and Buddhists were persecuted, with many of their stupas burned. Although strong supporters of Zoroastrianism, the Sassanids tolerated Buddhism and allowed the construction of more Buddhist monasteries. It was during their rule that the Lokottaravāda followers erected the two Buddha statues at Bamiyan.
During the second half of the third century, the Mobad Zoroastrian high priest Kirder dominated the religious policy of the state. He ordered the destruction of several Buddhist monasteries in Afghanistan, since the amalgam of Buddhism and Zoroastrianism manifested in the form of a "Buddha-Mazda" deity appeared to him as heresy. Buddhism quickly recovered after his death.
Pushyamitra Shunga.
The first persecution of Buddhists in India took place in the 2nd century BC by King Pushyamitra Shunga, although it has been continuously refuted by many historians on various reasons. A non-contemporary Buddhist text states that Pushyamitra cruelly persecuted Buddhists. While some scholars believe he did persecute Buddhists based on the Buddhist accounts, others consider them biased because of him not patronising them. Many other scholars have expressed skepticism about the Buddhist claims. Étienne Lamotte points out that the Buddhist legends are not consistent about the location of Pushyamitra's anti-Buddhist campaign and his death: "To judge from the documents, Pushyamitra must be acquitted through lack of proof." Agreeing with him, D. Devahuti states that Pushyamitra's sudden destruction after offering rewards for Buddhist heads is "manifestly false". R. C. Mitra states that "The tales of persecution by Pushyamitra as recorded in "Divyavadana" and by Taranatha bear marks of evident absurdity."
Hepthalites.
Central Asian and North Western Indian Buddhism weakened in the 6th century following the White Hun invasion who followed their own religions such as Tengri and Manichaeism. Around 440 CE they conquered Sogdiana then conquered Gandhara and pushed on into the Gangetic Plains. Their King Mihirkula who ruled from 515 CE suppressed Buddhism, destroying monasteries as far as modern-day Allahabad before his son reversed the policy.
Hun invasions (6th century).
Chinese scholars traveling through the region between the 5th and 8th centuries, such as Faxian, Xuanzang, Yijing, Hui-sheng, and Sung-Yun, began to speak of a decline of the Buddhist "Sangha" in the Northwestern parts of Indian subcontinent, especially in the wake of the Hun invasion from central Asia in the 6th century CE. Xuanzang wrote that numerous monasteries in north-western India had been reduced to ruins by the Huns.
The Hun ruler Mihirakula, who ruled from 515 CE in north-western region (modern Afghanistan, Pakistan and north India), suppressed Buddhism as well. He did this by destroying monasteries as far away as modern-day Prayagraj.
Pandyas and Pallavas.
After the Kalabhra interregnum, the Tamil states of the Pandyas and Pallavas reemerged, reviving the Saivite and Vaishnavite native religions. Further, the Saivite saint Thirugnanasambandar theologically defeated 8000 Sramanas with Buddhist names among them. When they rebelled, they were impaled by Koon Pandiyan at Samanatham near Madurai. Mahendravarma Pallava under Appar, a reformed Saivite saint destroyed Sramana monuments and wrote Mattavilasaprahasana, a comic play on the heretical (non Vedic) sects of the time including Buddhism. These events are considered to be the ushering in of the Bhakti era in India which resulted in the routing of Buddhism in the India.
Persecution under Hindus.
Another story is recounted by D N Jha, based on Rajatarangini, persecution of Buddhists also happened in the time of King Gonandiya-Ashoka (different from King Ashoka of Mauryan Empire). Jha writes that according to a book Rajatarangini, dated to the 12th century, Jalauka was a Shaivite and was responsible for the destruction of many Buddhist monasteries. The story of Jalauka is essentially legendary, and its to be noted that no independent corroboration of the Kashmir tradition has ever been discovered. Patanjali, a famous grammarian stated in his "Mahabhashya" that Brahmins and Śramaṇa, which included Buddhists, were eternal enemies. With the emergence of Hindu rulers of the Gupta Empire, Hinduism saw a major revivalism in the Indian subcontinent which challenged Buddhism which was at that time at its zenith. Even though Gupta empire was tolerant towards Buddhism and patronized Buddhist arts and religious institutions, Hindu revivalism generally became a major threat to Buddhism which led to its decline.
A Buddhist illustrated palm leaf manuscript from Pala period (one of the earliest Indian illustrated manuscripts to survive in modern times) is preserved in University of Cambridge library. Composed in the year 1015, the manuscript contains a note from the year 1138 by a Buddhist believer called Karunavajra which indicates that without his efforts, the manuscript would have been destroyed during a political struggle for power. The note states that 'he rescued the "Perfection of Wisdom", incomparable Mother of the Omniscient' from falling into the hands of unbelievers (who according to Camillo Formigatti were most probably people of Brahmanical affiliation). In 1794 Jagat Singh, Dewan (minister) of Raja Chet Singh of Banaras began excavating two pre Ashokan era stupas at Sarnath for construction material. Dharmarajika stupa was completely demolished and only its foundation exists today while Dhamekh stupa incurred serious damage. During excavation a green marble relic casket was discovered from Dharmarajika stupa which contained Buddha's ashes was subsequently thrown into Ganges river by Jagat Singh according to his Hindu faith. The incident was reported by a British resident and timely action of East India Company officials saved Dhamekh Stupa from demolition.
The Asokavadana legend has been likened to a Buddhist version of Pushyamitra's attack of the Mauryas, reflecting the declining influence of Buddhism in the Shunga Imperial court. Later Shunga kings were seen as amenable to Buddhism and as having contributed to the building of the stupa at Bharhut. The decline of Buddhism in India did not set in until the Gupta dynasty.
Archeological remains of stupas have been found in Deorkothar that suggest deliberate destruction, conjectured to be one mentioned in Divyavadana about Pushyamitra. However, it is unclear whether the stupas were destroyed in ancient India or a much later period, and the existence of religious violence between Hinduism and Buddhism in ancient India has been disputed. It is unclear when the Deorkothar stupas were destroyed, and by whom. The fictional tales of Divyavadana is considered by scholars as being of doubtful value as a historical record. Moriz Winternitz, for example, stated, "these legends [in the Divyāvadāna] scarcely contain anything of much historical value". Similarly, Paul Williams states that the persecution claims with alleged dates of Buddha's nirvana (400 BCE) and the subsequent Pusyamitra reign, as depicted in the Mahasanghika school of early Buddhism are the "most far fetched of all the arguments and hardly worth of any further discussion".
According to other scholars, the Shunga kings were seen as more amenable to Buddhism and as having contributed to the building of the stupa at Bharhut and an inscription at Bodh Gaya at the Mahabodhi Temple records the construction of the temple as follows, "The gift of Nagadevi the wife of King Brahmamitra". Another inscription reads: "The gift of Kurangi, the mother of living sons and the wife of King Indragnimitra, son of Kosiki. The gift also of Srima of the royal palace shrine."
Pandyas and Pallavas.
After the Kalabhra interregnum, the Tamil states of the Pandyas and Pallavas reemerged, reviving the Saivite and Vaishnavite native religions. Further, the Saivite saint Thirugnanasambandar theologically defeated 8000 Sramanas with Buddhist names among them. When they rebelled, they were impaled by Koon Pandiyan at Samanatham near Madurai. Mahendravarma Pallava under Appar, a reformed Saivite saint destroyed Sramana monuments and wrote Mattavilasaprahasana, a comic play on the heretical (non Vedic) sects of the time including Buddhism. These events are considered to be the ushering in of the Bhakti era in India which resulted in the routing of Buddhism in the India.
Persecution under other Kingdoms.
Emperor Wuzong of Tang.
Emperor Wuzong of Tang (814–846) indulged in indiscriminate religious persecution, solving a financial crisis by seizing the property of Buddhist monasteries. Buddhism had developed into a major religious force in Tang empire during the Tang period, and its monasteries had tax-exempt status. Wuzong closed many Buddhist shrines, confiscated their property, and sent the monks and nuns home to lay life. Apart from economic reasons, Wuzong's motivation was also philosophical or ideological. As a zealous Taoist, he considered Buddhism a foreign religion that was harmful to Chinese society. He went after other foreign religions as well, all but eradicating Zoroastrianism and Manichaeism in China, and his persecution of the growing Nestorian Christian churches sent Chinese Christianity into a decline from which it never recovered.
King Langdarma of Tibet.
Langdarma was a Tibetan King, who reigned from 838 to 841 CE. He is believed to have been anti-Buddhist and a follower of the Bön religion.
Oirat Mongols.
The Oirats (Western Mongols) converted to Tibetan Buddhism around 1615. The Dzungars were a confederation of several Oirat tribes that emerged suddenly in the early 17th century. The Dzungar Khanate was the last great nomadic empire in Asia. In the 18th century, the Dzungars were annihilated by Qianlong Emperor in several campaigns. About 80% of the Dzungar population, or around 500,000 to 800,000 people, were killed during or after the Zunghar Genocide by Manchu Bannermen and Khalkha Mongols during the Manchu conquest in 1755–1757.
The Kalmyk Khanate was founded in the 17th century with Tibetan Buddhism as its main religion, following the earlier migration of the Oirats from Dzungaria through Central Asia to the steppe around the mouth of the Volga River. During the course of the 18th century, they were absorbed by the Russian Empire, which was then expanding to the south and east. The Russian Orthodox church pressured many Kalmyks to adopt Orthodoxy. In the winter of 1770–1771, about 300,000 Kalmyks set out to return to China. Their goal was to retake control of Dzungaria from the Qing dynasty of China. Along the way many were attacked and killed by Kazakhs and Kyrgyz, their historical enemies based on intertribal competition for land, and many more died of starvation and disease. After several months of travel, only one-third of the original group reached Dzungaria and had no choice but to surrender to the Qing upon arrival.
Persecutions by Muslim Empires.
Arab invasions.
Qutaybah ibn Muslim, the Arab general of Khorasan conquered a number of territories in Central Asia including Samarkand where he broke a number of images. Several instances of Buddhist shrines being destroyed by the advancing Muslims are recorded though the religion continued to survive in some places for a considerable period of time. Bertolf Spuler cites the writings of Narshakhi while stating that the residents of Bukhara had reconverted from Islam to Buddhism four times until it was conquered by Qutayba in 712–13. A mosque was built in the city in place of a Buddhist monastery. Buddhists continued to live there until the tenth century. Similarly, Buddhism continued to exist in other places like Old Bukhara, Simingan in southern Tukharistan, Bamiyan and Kabul with suburbs inhabited by "Indians" which were also home to Buddhists. However, the religion could no longer develop as a power or distribute propaganda and its adherents also had to abandon the conversion of peoples in these regions. Scholars like Richard Nelson Frye have doubted the story of Marshaki, pointing out that unlike its statement, Qutayba ibn Muslim did not live during the time of Umayyad Caliph Mu'awiya, as this story suggests, but rather much later. In addition to discrimination, emigration, and the conversion of the laity, Buddhism and its monasteries also declined with the Muslims taking over the trade along the Silk Road as well as in Sindh.
During their conquest of Sindh, the Arabs brought the non-Muslims into the category of "ahl al-kitab", considering them "ahl al-dhimmah" (protected subjects) and thus practicing a certain amount of non-interference in their religious lives under the condition that they fulfil a number of obligations that came with this status. Since both Buddhism and Hinduism are literate religions with scriptures, the precedent of assimilating Zoroastrians into the category of