Question: When did the conquest of the region where BBC was banned from reporting reach its peak?

full_context: Document 1: 2008 Summer Olympics torch relay: In many cities along the North American and European route, the torch relay was protested by advocates of Tibetan independence, animal rights, and legal online gambling, and people protesting against China's human rights record, resulting in confrontations at a few of the relay locations. These protests, which ranged from hundreds of people in San Francisco, to effectively none in Pyongyang, forced the path of the torch relay to be changed or shortened on a number of occasions. The torch was extinguished by Chinese security officials several times during the Paris leg for security reasons, and once in protest in Paris.
Document 2: Sino-Tibetan relations during the Ming dynasty: Laird writes that Altan Khan abolished the native Mongol practices of shamanism and blood sacrifice, while the Mongol princes and subjects were coerced by Altan to convert to Gelug Buddhism—or face execution if they persisted in their shamanistic ways. Committed to their religious leader, Mongol princes began requesting the Dalai Lama to bestow titles on them, which demonstrated "the unique fusion of religious and political power" wielded by the Dalai Lama, as Laird writes. Kolmaš states that the spiritual and secular Mongol-Tibetan alliance of the 13th century was renewed by this alliance constructed by Altan Khan and Sönam Gyatso. Van Praag writes that this restored the original Mongol patronage of a Tibetan lama and "to this day, Mongolians are among the most devout followers of the Gelugpa and the Dalai Lama." Angela F. Howard writes that this unique relationship not only provided the Dalai Lama and Panchen Lama with religious and political authority in Tibet, but that Altan Khan gained "enormous power among the entire Mongol population."
Document 3: 2008 Summer Olympics torch relay: A Macau resident was arrested on April 26 for posting a message on cyberctm.com encouraging people to disrupt the relay. Both orchidbbs.com and cyberctm.com Internet forums were shut down from May 2 to 4. This fueled speculation that the shutdowns were targeting speeches against the relay. The head of the Bureau of Telecommunications Regulation has denied that the shutdowns of the websites were politically motivated. About 2,200 police were deployed on the streets, there were no interruptions.
Document 4: 2008 Summer Olympics torch relay: Some Western media have reported on Chinese accusations of Western media bias. The Daily Telegraph published an opinion piece by the Chinese ambassador to the United Kingdom, Fu Ying, who accused Western media of "demonising" China during their coverage of the torch relays. The Telegraph also asked its readers to send their views in response to the question "Is the West demonising China?" The BBC reported on a demonstration in Sydney by Chinese Australians "voicing support for Beijing amid controversy over Tibet" and protesting against what they saw as Western media bias. The report showed demonstrators carrying signs which read "Shame on some Western media", "BBC CNN lies too" and "Stop media distortion!". One demonstrator interviewed by the BBC stated: "I saw some news from CNN, from the BBC, some media [inaudible], and they are just lying." Libération also reported that it had been accused of bias by the Chinese media.
Document 5: Sino-Tibetan relations during the Ming dynasty: With the example of the Ming court's relationship with the fifth Karmapa and other Tibetan leaders, Norbu states that Chinese Communist historians have failed to realize the significance of the religious aspect of the Ming-Tibetan relationship. He writes that the meetings of lamas with the Emperor of China were exchanges of tribute between "the patron and the priest" and were not merely instances of a political subordinate paying tribute to a superior. He also notes that the items of tribute were Buddhist artifacts which symbolized "the religious nature of the relationship." Josef Kolmaš writes that the Ming dynasty did not exercise any direct political control over Tibet, content with their tribute relations that were "almost entirely of a religious character." Patricia Ann Berger writes that the Yongle Emperor's courting and granting of titles to lamas was his attempt to "resurrect the relationship between China and Tibet established earlier by the Yuan dynastic founder Khubilai Khan and his guru Phagpa." She also writes that the later Qing emperors and their Mongol associates viewed the Yongle Emperor's relationship with Tibet as "part of a chain of reincarnation that saw this Han Chinese emperor as yet another emanation of Manjusri."
Document 6: Sino-Tibetan relations during the Ming dynasty: The Ming initiated sporadic armed intervention in Tibet during the 14th century, but did not garrison permanent troops there. At times the Tibetans also used armed resistance against Ming forays. The Wanli Emperor (r. 1572–1620) made attempts to reestablish Sino-Tibetan relations after the Mongol-Tibetan alliance initiated in 1578, which affected the foreign policy of the subsequent Qing dynasty (1644–1912) of China in their support for the Dalai Lama of the Gelug school. By the late 16th century, the Mongols were successful armed protectors of the Gelug Dalai Lama, after increasing their presence in the Amdo region. This culminated in Güshi Khan's (1582–1655) conquest of Tibet from 1637–1642 and the establishment of the Ganden Phodrang regime by the 5th Dalai Lama with his help.
Document 7: 2008 Summer Olympics torch relay: On April 19, the BBC reported that 1,300 people had gathered outside BBC buildings in Manchester and London, protesting against what they described as Western media bias. Several days earlier, the BBC had published an article entitled "The challenges of reporting in China", responding to earlier criticism. The BBC's Paul Danahar noted that Chinese people were now "able to access the BBC News website for the first time, after years of strict censorship", and that "many were critical of our coverage". He provided readers with a reminder of censorship in China, and added: "People who criticise the media for their coverage in Tibet should acknowledge that we were and still are banned from reporting there." He also quoted critical Chinese responses, and invited readers to comment.
Document 8: 2008 Summer Olympics torch relay: In response to the demonstrations, the Chinese government attempted to calm the situation, possibly fearing the protests may spiral out of control as has happened in recent years, including the anti-Japanese protests in 2005. State media and commentaries began to call for calm, such as an editorial in the People's Daily which urged Chinese people to "express [their] patriotic enthusiasm calmly and rationally, and express patriotic aspiration in an orderly and legal manner". The government also began to patrol and censor the internet forums such as Sohu.com, with comments related to the Carrefour boycott removed. In the days prior to the planned boycott, evidence of efforts by Chinese authorities to choke the mass boycott's efforts online became even more evident, including barring searches of words related to the French protests, but protests broke out nonetheless in front of Carrefour's stores at Beijing, Changsha, Fuzhou and Shenyang on May 1.
Document 9: 2008 Summer Olympics torch relay: On April 17, Xinhua condemned what it called "biased coverage of the Lhasa riots and the Olympic torch relay by the U.S.-based Cable News Network (CNN)". The same day, the Chinese government called on CNN to "apologise" for having allegedly insulted the Chinese people, and for "attempting to incite the Chinese people against the government". CNN issued a statement on April 14, responded to China over 'thugs and goons' comment by Jack Cafferty.
Document 10: Sino-Tibetan relations during the Ming dynasty: Kolmaš writes that, as the Mongol presence in Tibet increased, culminating in the conquest of Tibet by a Mongol leader in 1642, the Ming emperors "viewed with apparent unconcern these developments in Tibet." He adds that the Ming court's lack of concern for Tibet was one of the reasons why the Mongols pounced on the chance to reclaim their old vassal of Tibet and "fill once more the political vacuum in that country." On the mass Mongol conversion to Tibetan Buddhism under Altan Khan, Laird writes that "the Chinese watched these developments with interest, though few Chinese ever became devout Tibetan Buddhists."
Document 11: 2008 Summer Olympics torch relay: Chinese officials canceled the torch relay ceremony amidst disruptions, including a Tibetan flag flown from a window in the City Hall by Green Party officials. The third torchbearer in the Paris leg, Jin Jing, who was disabled and carried the torch on a wheelchair, was assaulted several times by unidentified protestors seemingly from the pro-Tibet independent camp. In interviews, Jin Jing said that she was "tugged at, scratched" and "kicked", but that she "did not feel the pain at the time." She received praise from ethnic Chinese worldwide as "Angel in Wheelchair". The Chinese government gave the comment that "the Chinese respect France a lot" but "Paris [has slapped] its own face."
Document 12: Sino-Tibetan relations during the Ming dynasty: Discussions of strategy in the mid Ming dynasty focused primarily on recovery of the Ordos region, which the Mongols used as a rallying base to stage raids into Ming China. Norbu states that the Ming dynasty, preoccupied with the Mongol threat to the north, could not spare additional armed forces to enforce or back up their claim of sovereignty over Tibet; instead, they relied on "Confucian instruments of tribute relations" of heaping unlimited number of titles and gifts on Tibetan lamas through acts of diplomacy. Sperling states that the delicate relationship between the Ming and Tibet was "the last time a united China had to deal with an independent Tibet," that there was a potential for armed conflict at their borders, and that the ultimate goal of Ming foreign policy with Tibet was not subjugation but "avoidance of any kind of Tibetan threat." P. Christiaan Klieger argues that the Ming court's patronage of high Tibetan lamas "was designed to help stabilize border regions and protect trade routes."
Document 13: Sino-Tibetan relations during the Ming dynasty: Nevertheless, the ethno-geographic caste hierarchy favoring the Mongols and other ethnicities were accorded higher status than the Han Chinese majority. Although Han Chinese who were recruited as advisers were often actually more influential than high officials, their status was not as well defined. Kublai also abolished the imperial examinations of China's civil service legacy, which was not reinstated until Ayurbarwada Buyantu Khan's reign (1311–1320). Rossabi writes that Kublai recognized that in order to rule China, "he had to employ Chinese advisors and officials, yet he could not rely totally on Chinese advisers because he had to maintain a delicate balancing act between ruling the sedentary civilization of China and preserving the cultural identity and values of the Mongols." And "in governing China, he was concerned with the interests of his Chinese subjects, but also with exploiting the resources of the empire for his own aggrandizement. His motivations and objectives alternated from one to the other throughout his reign," according to Rossabi. Van Praag writes in The Status of Tibet that the Tibetans and Mongols, on the other hand, upheld a dual system of rule and an interdependent relationship that legitimated the succession of Mongol khans as universal Buddhist rulers, or chakravartin. Van Praag writes that "Tibet remained a unique part of the Empire and was never fully integrated into it," citing examples such as a licensed border market that existed between China and Tibet during the Yuan.
Document 14: Sino-Tibetan relations during the Ming dynasty: Patricia Ebrey writes that Tibet, like Joseon Korea and other neighboring states to the Ming, settled for its tributary status while there were no troops or governors of Ming China stationed in its territory. Laird writes that "after the Mongol troops left Tibet, no Ming troops replaced them." Wang and Nyima state that, despite the fact that the Ming refrained from sending troops to subdue Tibet and refrained from garrisoning Ming troops there, these measures were unnecessary so long as the Ming court upheld close ties with Tibetan vassals and their forces. However, there were instances in the 14th century when the Hongwu Emperor did use military force to quell unrest in Tibet. John D. Langlois writes that there was unrest in Tibet and western Sichuan, which the Marquis Mu Ying (沐英) was commissioned to quell in November 1378 after he established a Taozhou garrison in Gansu. Langlois notes that by October 1379, Mu Ying had allegedly captured 30,000 Tibetan prisoners and 200,000 domesticated animals. Yet invasion went both ways; the Ming general Qu Neng, under the command of Lan Yu, was ordered to repel a Tibetan assault into Sichuan in 1390.
Document 15: 2008 Summer Olympics torch relay: Thailand: The April 18 relay through Bangkok was the Olympic flame's first visit to Thailand. The relay covered just over 10 km, and included Bangkok's Chinatown. The torch was carried past Democracy Monument, Chitralada Palace and a number of other city landmarks. M.R. Narisa Chakrabongse, Green World Foundation (GWF) chairwoman, withdrew from the torch-running ceremony, protesting against China's actions in Tibet. Several hundred protesters were present, along with Olympic supporters. Thai authorities threatened to arrest foreign protesters and ban them from future entry into Thailand. A coalition of Thai human rights groups announced that it would organise a "small demonstration" during the relay, and several hundred people did indeed take part in protests, facing Beijing supporters. Intended torchbearer Mom Rajawongse Narissara Chakrabongse boycotted the relay, to protest against China's actions in Tibet. In Bangkok, students told the media that the Chinese Embassy provided them with transportation and gave them shirts to wear.
ground_truth: 1642
sub_queries: Where is BBC banned from reporting? Answer: Tibet
When did the conquest of Tibet reach its peak? Answer: 1642