Question: What is the highest elevation in the region that traded horses with Ming?

full_context: Document 1: 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 2: Mount Everest: Mount Everest, known in Nepali as Sagarmatha (सगरमाथा) and in Tibetan as Chomolungma (ཇོ ་ མོ ་ གླང ་ མ), is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The international border between Nepal (Province No. 1) and China (Tibet Autonomous Region) runs across its summit point.
Document 3: Tibet: The Indus and Brahmaputra rivers originate from a lake (Tib: Tso Mapham) in Western Tibet, near Mount Kailash. The mountain is a holy pilgrimage site for both Hindus and Tibetans. The Hindus consider the mountain to be the abode of Lord Shiva. The Tibetan name for Mt. Kailash is Khang Rinpoche. Tibet has numerous high-altitude lakes referred to in Tibetan as tso or co. These include Qinghai Lake, Lake Manasarovar, Namtso, Pangong Tso, Yamdrok Lake, Siling Co, Lhamo La-tso, Lumajangdong Co, Lake Puma Yumco, Lake Paiku, Lake Rakshastal, Dagze Co and Dong Co. The Qinghai Lake (Koko Nor) is the largest lake in the People's Republic of China.
Document 4: Tibet: The modern Standard Chinese exonym for the ethnic Tibetan region is Zangqu (Chinese: 藏区; pinyin: Zàngqū), which derives by metonymy from the Tsang region around Shigatse plus the addition of a Chinese suffix, 区 qū, which means "area, district, region, ward". Tibetan people, language, and culture, regardless of where they are from, are referred to as Zang (Chinese: 藏; pinyin: Zàng) although the geographical term Xīzàng is often limited to the Tibet Autonomous Region. The term Xīzàng was coined during the Qing dynasty in the reign of the Jiaqing Emperor (1796–1820) through the addition of a prefix meaning "west" (西 xī) to Zang.
Document 5: Sino-Tibetan relations during the Ming dynasty: Meanwhile, the Tumed Mongols began moving into the Kokonor region (modern Qinghai), raiding the Ming Chinese frontier and even as far as the suburbs of Beijing under Altan Khan (1507–1582). Klieger writes that Altan Khan's presence in the west effectively reduced Ming influence and contact with Tibet. After Altan Khan made peace with the Ming dynasty in 1571, he invited the third hierarch of the Gelug—Sönam Gyatso (1543–1588)—to meet him in Amdo (modern Qinghai) in 1578, where he accidentally bestowed him and his two predecessors with the title of Dalai Lama—"Ocean Teacher". The full title was "Dalai Lama Vajradhara", "Vajradhara" meaning "Holder of the Thunderbolt" in Sanskrit. Victoria Huckenpahler notes that Vajradhara is considered by Buddhists to be the primordial Buddha of limitless and all-pervasive beneficial qualities, a being that "represents the ultimate aspect of enlightenment." Goldstein writes that Sönam Gyatso also enhanced Altan Khan's standing by granting him the title "king of religion, majestic purity". Rawski writes that the Dalai Lama officially recognized Altan Khan as the "Protector of the Faith".
Document 6: Sino-Tibetan relations during the Ming dynasty: While the Ming dynasty traded horses with Tibet, it upheld a policy of outlawing border markets in the north, which Laird sees as an effort to punish the Mongols for their raids and to "drive them from the frontiers of China." However, after Altan Khan (1507–1582)—leader of the Tümed Mongols who overthrew the Oirat Mongol confederation's hegemony over the steppes—made peace with the Ming dynasty in 1571, he persuaded the Ming to reopen their border markets in 1573. This provided the Chinese with a new supply of horses that the Mongols had in excess; it was also a relief to the Ming, since they were unable to stop the Mongols from periodic raiding. Laird says that despite the fact that later Mongols believed Altan forced the Ming to view him as an equal, Chinese historians argue that he was simply a loyal Chinese citizen. By 1578, Altan Khan formed a formidable Mongol-Tibetan alliance with the Gelug that the Ming viewed from afar without intervention.
Document 7: Tibet: Tibet has some of the world's tallest mountains, with several of them making the top ten list. Mount Everest, located on the border with Nepal, is, at 8,848 metres (29,029 ft), the highest mountain on earth. Several major rivers have their source in the Tibetan Plateau (mostly in present-day Qinghai Province). These include the Yangtze, Yellow River, Indus River, Mekong, Ganges, Salween and the Yarlung Tsangpo River (Brahmaputra River). The Yarlung Tsangpo Grand Canyon, along the Yarlung Tsangpo River, is among the deepest and longest canyons in the world.
Document 8: Sino-Tibetan relations during the Ming dynasty: Tsai writes that shortly after the visit by Deshin Shekpa, the Yongle Emperor ordered the construction of a road and of trading posts in the upper reaches of the Yangzi and Mekong Rivers in order to facilitate trade with Tibet in tea, horses, and salt. The trade route passed through Sichuan and crossed Shangri-La County in Yunnan. Wang and Nyima assert that this "tribute-related trade" of the Ming exchanging Chinese tea for Tibetan horses—while granting Tibetan envoys and Tibetan merchants explicit permission to trade with Han Chinese merchants—"furthered the rule of the Ming dynasty court over Tibet". Rossabi and Sperling note that this trade in Tibetan horses for Chinese tea existed long before the Ming. Peter C. Perdue says that Wang Anshi (1021–1086), realizing that China could not produce enough militarily capable steeds, had also aimed to obtain horses from Inner Asia in exchange for Chinese tea. The Chinese needed horses not only for cavalry but also as draft animals for the army's supply wagons. The Tibetans required Chinese tea not only as a common beverage but also as a religious ceremonial supplement. The Ming government imposed a monopoly on tea production and attempted to regulate this trade with state-supervised markets, but these collapsed in 1449 due to military failures and internal ecological and commercial pressures on the tea-producing regions.
Document 9: Tibet: The Tibetan name for their land, Bod བོད་, means "Tibet" or "Tibetan Plateau", although it originally meant the central region around Lhasa, now known in Tibetan as Ü. The Standard Tibetan pronunciation of Bod, [pʰøʔ˨˧˨], is transcribed Bhö in Tournadre Phonetic Transcription, Bö in the THL Simplified Phonetic Transcription and Poi in Tibetan pinyin. Some scholars believe the first written reference to Bod "Tibet" was the ancient Bautai people recorded in the Egyptian Greek works Periplus of the Erythraean Sea (1st century CE) and Geographia (Ptolemy, 2nd century CE), itself from the Sanskrit form Bhauṭṭa of the Indian geographical tradition.
Document 10: Tibet: Historically, the population of Tibet consisted of primarily ethnic Tibetans and some other ethnic groups. According to tradition the original ancestors of the Tibetan people, as represented by the six red bands in the Tibetan flag, are: the Se, Mu, Dong, Tong, Dru and Ra. Other traditional ethnic groups with significant population or with the majority of the ethnic group residing in Tibet (excluding a disputed area with India) include Bai people, Blang, Bonan, Dongxiang, Han, Hui people, Lhoba, Lisu people, Miao, Mongols, Monguor (Tu people), Menba (Monpa), Mosuo, Nakhi, Qiang, Nu people, Pumi, Salar, and Yi people.
Document 11: 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 12: 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 13: Sino-Tibetan relations during the Ming dynasty: Laird writes that the Ming appointed titles to eastern Tibetan princes, and that "these alliances with eastern Tibetan principalities are the evidence China now produces for its assertion that the Ming ruled Tibet," despite the fact that the Ming did not send an army to replace the Mongols after they left Tibet. Yiu Yung-chin states that the furthest western extent of the Ming dynasty's territory was Gansu, Sichuan, and Yunnan while "the Ming did not possess Tibet."
Document 14: 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 15: 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."
ground_truth: Mount Everest
sub_queries: Who did the Ming trade horses with? Answer: Tibet
What is the highest elevation in Tibet ? Answer: Mount Everest