Question: When did the conquest of the country whose capitol is Lhasa reach its peak?

full_context: Document 1: Tibet: Standing at 117 metres (384 feet) in height and 360 metres (1,180 feet) in width, the Potala Palace is the most important example of Tibetan architecture. Formerly the residence of the Dalai Lama, it contains over one thousand rooms within thirteen stories, and houses portraits of the past Dalai Lamas and statues of the Buddha. It is divided between the outer White Palace, which serves as the administrative quarters, and the inner Red Quarters, which houses the assembly hall of the Lamas, chapels, 10,000 shrines, and a vast library of Buddhist scriptures. The Potala Palace is a World Heritage Site, as is Norbulingka, the former summer residence of the Dalai Lama.
Document 2: Tibet: The Tibetan Empire emerged in the 7th century, but with the fall of the empire the region soon divided into a variety of territories. The bulk of western and central Tibet (Ü-Tsang) was often at least nominally unified under a series of Tibetan governments in Lhasa, Shigatse, or nearby locations; these governments were at various times under Mongol and Chinese overlordship. The eastern regions of Kham and Amdo often maintained a more decentralized indigenous political structure, being divided among a number of small principalities and tribal groups, while also often falling more directly under Chinese rule after the Battle of Chamdo; most of this area was eventually incorporated into the Chinese provinces of Sichuan and Qinghai. The current borders of Tibet were generally established in the 18th century.
Document 3: 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 4: 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 5: 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 6: Tibet: There are over 800 settlements in Tibet. Lhasa is Tibet's traditional capital and the capital of Tibet Autonomous Region. It contains two world heritage sites -- the Potala Palace and Norbulingka, which were the residences of the Dalai Lama. Lhasa contains a number of significant temples and monasteries, including Jokhang and Ramoche Temple.
Document 7: Tibet: Tibet (i/tᵻˈbɛt/; Wylie: Bod, pronounced [pʰø̀ʔ]; Chinese: 西藏; pinyin: Xīzàng) is a region on the Tibetan Plateau in Asia. It is the traditional homeland of the Tibetan people as well as some other ethnic groups such as Monpa, Qiang and Lhoba peoples and is now also inhabited by considerable numbers of Han Chinese and Hui people. Tibet is the highest region on Earth, with an average elevation of 4,900 metres (16,000 ft). The highest elevation in Tibet is Mount Everest, earth's highest mountain rising 8,848 m (29,029 ft) above sea level.
Document 8: 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 9: Tibet: The language has numerous regional dialects which are generally not mutually intelligible. It is employed throughout the Tibetan plateau and Bhutan and is also spoken in parts of Nepal and northern India, such as Sikkim. In general, the dialects of central Tibet (including Lhasa), Kham, Amdo and some smaller nearby areas are considered Tibetan dialects. Other forms, particularly Dzongkha, Sikkimese, Sherpa, and Ladakhi, are considered by their speakers, largely for political reasons, to be separate languages. However, if the latter group of Tibetan-type languages are included in the calculation, then 'greater Tibetan' is spoken by approximately 6 million people across the Tibetan Plateau. Tibetan is also spoken by approximately 150,000 exile speakers who have fled from modern-day Tibet to India and other countries.
Document 10: Himalayas: In Hinduism, the Himalayas have been personified as the king of all Mountain – "Giriraj Himavat", father of Ganga and Parvati (form of Adi Shakti Durga).A number of Vajrayana Buddhist sites are situated in the Himalayas, in Tibet, Bhutan and in the Indian regions of Ladakh, Sikkim, Arunachal Pradesh, Spiti and Darjeeling. There were over 6,000 monasteries in Tibet, including the residence of the Dalai Lama. Bhutan, Sikkim and Ladakh are also dotted with numerous monasteries. The Tibetan Muslims have their own mosques in Lhasa and Shigatse.
Document 11: 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 12: Kathmandu: Legendary Princess Bhrikuti (7th-century) and artist Araniko (1245 - 1306 AD) from that tradition of Kathmandu valley played a significant role in spreading Buddhism in Tibet and China. There are over 108 traditional monasteries (Bahals and Bahis) in Kathmandu based on Newar Buddhism. Since the 1960s, the permanent Tibetan Buddhist population of Kathmandu has risen significantly so that there are now over fifty Tibetan Buddhist monasteries in the area. Also, with the modernization of Newar Buddhism, various Theravada Bihars have been established.
Document 13: Potala Palace: The Potala Palace (Tibetan: ཕོ ་ བྲང ་ པོ ་ ཏ ་ ལ ་, Wylie: pho brang Potala) in Lhasa, Tibet Autonomous Region, China was the residence of the Dalai Lama until the 14th Dalai Lama fled to India during the 1959 Tibetan uprising. It is now a museum and World Heritage Site.
Document 14: 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 15: 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."
ground_truth: 1642
sub_queries: lhasa which is being turned into a culturally chinese city is the capital of what country Answer: Tibet
When did the conquest of Tibet reach its peak? Answer: 1642