Editing Tumu Crisis (section)

==Background==
===Military situation===
The [[Ming dynasty]] was established in 1368 when [[Zhu Yuanzhang (the Hongwu Emperor)]], a former peasant rebel, overthrew the Mongol-led [[Yuan dynasty]] and forced the Mongols to retreat back to the northern steppes.{{sfnp|Dardess|2012|pp=1–15}} To counter persistent Mongol threats along the northern frontier, the Hongwu Emperor implemented significant military reforms and launched multiple military campaigns to secure the border regions.{{sfnp|Mote|2003|pp=543–547}} His son, the [[Yongle Emperor]], further expanded these efforts by personally leading expeditions against Mongol forces between 1410 and 1424.{{sfnp|Chan|1988|pp=227–235}} The decision to move the capital to Beijing in 1421 was also a strategic move to focus on northern defense.{{sfnp|Chan|1988|pp=241–243}} While these aggressive policies initially strengthened frontier security, they ultimately depleted Ming military resources too thin.{{sfnp|Brook|2010|pp=78–81}}

After the death of the Yongle Emperor in 1424, the defense of the northern borders began to deteriorate. Despite complaints from generals about the lack of resources, no action was taken. In 1435 and 1438, some garrisons were reinforced, but the overall situation remained unchanged. Inland, only half of the supposed 2.5&nbsp;million soldiers in the ''Weisuo'' garrison system were actually performing their duties. Hereditary soldiers from ''Weisuo'' garrisons were often exploited by officers, leading to a reliance on inadequate grain supplies from the interior. This led to a decline in the quality of training, weapons, and equipment declined.{{sfnp|Twitchett|Grimm|1988|pp=319–320}} The Beijing garrison was frequently used for construction projects, such as defensive positions, but more often for the building of palaces, temples, and private residences for officers and [[Eunuchs in China|eunuchs]] of the imperial palace.{{sfnp|de Heer|1986|p=14}}

The defense of the northern border was primarily focused on the area between China and [[Mongolian–Manchurian grassland|the steppe]], as the outposts in present-day [[Inner Mongolia]] had been abandoned.{{efn|During the reign of the Yongle Emperor, the outposts in present-day [[Inner Mongolia]] were abandoned due to financial issues.{{sfnp|Chan|1988|p=248}} The only exception was the garrison in [[Shangdu|Kaiping]], which was isolated and difficult to defend. As a result, the Ming army abandoned it in 1430.{{sfnp|Wang|2011|p=116}}}} The [[Great Wall of China|Great Wall]] had not yet been constructed and the border was only guarded by patrols between fortified cities. The defense of the northeast relied on three main fortified cities: [[Xuanfu Garrison|Xuanfu]], [[Datong Garrison|Datong]], and Beijing. The fortifications of Beijing were not completed until 1445. In Xuanfu, there were 90,000 soldiers, with 35,000 ready for battle and 55,000 in training. Additionally, there were 25,000 horsemen and 9,000 firearms of various types,{{efn|3,000 each of heavy mortars, light hand guns, and the signal guns.{{sfnp|Twitchett|Grimm|1988|p=321}}}} as well as 90,000 [[Fire arrow|hand rockets]].{{sfnp|Twitchett|Grimm|1988|p=321}} Datong had a stronger cavalry force, with 35,000 horses, and was supported by 160,000 men in Beijing. The reserve consisted of garrisons stationed in northeastern China, specifically in [[North Zhili]], [[Shandong]], and [[Henan]].{{sfnp|Twitchett|Grimm|1988|p=321}}

The border patrol battalions were meant to hold off the enemy until the main forces arrived, but with Xuanfu only 180 km from Beijing, the defense system lacked depth{{sfnp|Twitchett|Grimm|1988|p=321}} and relied on a quick and decisive response to any attack.{{sfnp|Twitchett|Grimm|1988|p=322}}

===Sino–Mongol relations===
The Mongols were divided into three groups: the [[Uriankhai]] in the southeast, the [[Tatar (Mongolia)|Eastern Mongols]] (also known as Tatars) in the east, and the [[Oirats]] in the west.{{sfnp|Twitchett|Grimm|1988|p=316}} After [[Arughtai]], leader of the Eastern Mongols, was defeated in 1434, the Oirats took control over [[Mongolian Plateau]]. Their chief, Toghon, the [[Choros (Oirats)|Choros]] taishi, or "grand marshal", strengthened their authority by arranging for his daughter to marry the young khan of the Eastern Mongols, [[Taisun Khan|Toghtoa Bukha]].{{efn|A puppet khan installed by Toghon in 1439. Toghon was not a descendant of Genghis and therefore could not become a khan, even though he effectively ruled over Mongolia.{{sfnp|Twitchett|Grimm|1988|p=317}}{{sfnp|de Heer|1986|p=13}}}} After Toghon's death in 1440, his son [[Esen Taishi|Esen]] inherited the title of taishi, and "de facto ruler of all Mongols".{{sfnp|de Heer|1986|p=13}} Esen was more ambitious than his father, and in 1443 and 1445, he launched attacks on [[Hami]], an important city on the route from China to Central Asia near the Chinese border. In 1448, he successfully conquered it. He also attempted to gain the support of the Mongol divisions in the Ming army in the western Chinese province of [[Gansu]]. In the east, his authority extended to the borders of Korea.{{sfnp|Twitchett|Grimm|1988|p=317}} In Beijing, he was viewed as a threat by those who opposed [[Wang Zhen (eunuch)|Wang Zhen]], a powerful eunuch who held great influence at the imperial court in the 1440s.{{sfnp|de Heer|1986|p=14}}{{efn|Wang Zhen profited from illegal trade activities, such as selling metal tools and weapons to the Oirats. As a result, he ignored proposals to strengthen defenses on the northern border and warnings about threats from Esen.{{sfnp|de Heer|1986|p=15}}}}

In their relationship with China, the Mongols were primarily interested in free trade, specifically in the exchange of horses for tea, silk, and other luxury goods. However, the Ming government imposed restrictions and regulations on trade, limiting it to a few designated border towns, with Datong being the main hub.{{sfnp|Twitchett|Grimm|1988|p=317}} As Esen's power and influence expanded, so did his dependence on these goods to maintain the loyalty of the Mongol tribes.{{sfnp|de Heer|1986|p=15}} This led to a significant number of Mongols in border markets in the late 1440s, with up to two thousand arriving each year.{{sfnp|Twitchett|Grimm|1988|p=317}} The large number of armed horsemen posed a serious security concern for the Ming authorities.{{sfnp|Twitchett|Grimm|1988|p=317}} As a result, the Ming government protested against the excessive number of incoming Mongols, causing a sharp deterioration in their relationship. In 1449, the Ming ultimately rejected the Mongols' request for goods and only provided them with a fifth of what was requested. This rejection led the Mongols to resort to force. The immediate cause of the war was Ming's refusal to grant Esen's request to marry an imperial princess for his son.{{sfnp|de Heer|1986|p=15}}