On November 11, 1861, at the age of five (6 sui), Emperor Tongzhi formally ascended to the throne. Most of his first 11 years were spent in study, during which time much happened in China. The rebellions that had racked the country were suppressed. A policy of appeasement, rather than confrontation, was adopted in dealing with the outside. This latter change was primarily the work of Prince Gong.
While there had most likely been hopes that the Tongzhi Emperor would become a leader like the Kangxi Emperor (who ascended the throne as a child in 1661), those hopes would soon come to naught, as the Tongzhi Emperor grew up to become an obstinate and dissolute young man.
In the fall of 1872, the teenage emperor married Empress Xiaozheyi and several concubines. The Tongzhi Emperor apparently had wanted to take up power immediately, prompting a quarrel at court regarding the dismantling of the regency and the timing of it. However, the two empress dowagers stuck by the intended date of February 23, 1873.
The day after the Tongzhi Emperor took up the reins of power, the foreign powers requested an audience with the teenage emperor. The request precipitated a sharp disagreement between the ministers at the foreign legations, who made it clear that they would not perform the ritual kowtow to the emperor, and the Zongli Yamen (foreign affairs ministry), regarding the protocol to be observed. The Qing government was also loath to hold the audience within the confines of the Forbidden City, eventually settling on the "Pavilion of Purple Light" at one of the lakeside palaces to the west of the Forbidden City, which is now part of Zhongnanhai. The audience was finally held on 29 June 1873. After the audience, however, the foreign representatives made it clear their annoyance of being received at a hall initially used by the Qing emperors to receive envoys of tributary states.
In the fall of 1874, the Tongzhi Emperor got into a clash with his ministers, which included his two uncles, Prince Gong and Prince Chun, largely over the emperor's plans to rebuild the Old Summer Palace at a time in which the empire was bankrupt, and over his dissolute behavior. The emperor reacted by firing the ministers, but Empress Dowagers Ci'an and Cixi intervened, and he had them reinstated. That December, it was announced that he was ill with smallpox, and the empress dowagers resumed the regency. He died on 12 January 1875, leaving no sons to succeed him.
The Tongzhi Emperor's death left the court in a succession crisis, as, although he was childless, his empress was reportedly pregnant. Eventually, the empress dowagers designated the Tongzhi Emperor's three-year-old cousin, Zaitian, as the heir to the throne. Zaitian was biologically Prince Chun's son, but was symbolically adopted as the Xianfeng Emperor's son to make him eligible to succeed the Tongzhi Emperor. Zaitian was thus enthroned as the Guangxu Emperor, with Empress Dowagers Ci'an and Cixi resuming their roles as regents. The Tongzhi Emperor's empress died a few months later.
In 1872 Emperor Tongzhi reached his majority and was married. Cixi had selected another woman to be his wife, and she was not pleased that he went against her wishes. She reportedly made sure that their happiness was limited. According to some accounts, one way that she did this was to encourage the emperor to frequently visit outside pleasure quarters, where he supposedly engaged in bisexual debauchery and may have contracted syphilis.
In February 1873, Emperor Tongzhi began his personal rule. Unfortunately, the pet project he devoted himself to, the rebuilding of the summer palace, soon became the object of a rather notorious scandal. Shortly thereafter the nineteen-year-old emperor is said to have become infected with smallpox. Whatever the actual cause, smallpox or syphilis, Emperor Tongzhi died on January 12, 1875. Rumor has it that his wife, who was with child, was encouraged by Cixi to follow her husband in death. She did so on January 16, 1875.