In early March 1651 after Dorgon's supporters had been purged from the court, these titles were abrogated. The reign of the Shunzhi Emperor ended when he died of smallpox in 1661 at the age of 22. His last will—which was tampered and perhaps even forged by its beneficiaries—appointed four co-regents for his son and successor the six-year-old Xuanye, who was to reign as the Kangxi Emperor. All four were Manchu dignitaries who had supported the Shunzhi Emperor after the death of Dorgon, but their Manchu nativist measures reversed many of the Shunzhi Emperor's own policies. The "Oboi regency", named after the most powerful of the four regents, lasted until 1669, when the Kangxi Emperor started his personal rule. For almost 200 years, the Qing Empire was governed by adult emperors. In the last fifty years of the dynasty—from the death of the Xianfeng Emperor in 1861 to the final abdication of the child emperor Puyi in 1912—the imperial position again became vulnerable to the power of regents, empress dowagers, imperial uncles, and eunuchs. Empress Dowager Cixi (1835–1908) came to power through a coup that ousted eight regents who had been named by her husband, the Xianfeng Emperor. She controlled the government during the reigns of the Tongzhi (r. 1861–1875) and Guangxu (r. 1875–1908) emperors. From 1861 onwards, she was officially co-regent with Empress Dowager Ci'an, but her political role increased so much that within a few years she was taking charge of most government matters. She became sole regent in 1881 after the death of Empress Dowager Ci'an. With the assistance of eunuchs and Manchu princes, she remained regent until March 1889, when she finally let the Guangxu Emperor rule personally (he was then 28 years old). After she intervened to end the Hundred Days' Reform in September 1898, she had the emperor put under house arrest and held the reins of the Qing government until her death in 1908. An emperor's era name or reign name was chosen at the beginning of his reign to reflect the political concerns of the court at the time. A new era name became effective on the first day of the Chinese New Year after that emperor's accession, which fell between 21 January and 20 February (inclusively) of the Gregorian calendar.