How did the Mongols treat people who surrendered voluntarily?

When populations or military commanders surrendered voluntarily to the Mongol empire, they were often spared from the destruction and indiscriminate slaughter that characterized Mongol conquests of resisting cities.12

For example, during the Mongol invasion of the Song state, the Chinese commander of the key fortress at Xiangyang surrendered in 1273 after securing a solemn promise from the Mongols to spare the local population. Following this agreement, the commander was permitted to take office under his former enemies. Similarly, as Mongol forces advanced toward the Song capital of Lin’an, several prefectures along the Yangtze River surrendered voluntarily and were treated with relative restraint compared to those that resisted.2

While the Mongols were known for their military prowess and, at times, extreme violence, their rule was also defined by a "military patronage state" model. This system involved a reciprocal relationship where the conquerors relied on the administrative and technical skills of the subject population to maintain and rebuild urban life.1