During the late 1870s, Empress Dowager Cixi became ill from liver problems, so Empress Dowager Ci'an had to rule on her own. During this time, she had to deal with the war with the Russian Empire over Ili Prefecture. In 1871, the Dungan Revolt broke out in Xinjiang. The Qing Empire soon lost power and the Russians occupied the Ili basin region. The Qing government regained control over Xinjiang in 1877. In 1879, the Russians suggested that they maintain a strong presence in the region but the Qing government did not agree. The conflict ended with the signing of the Treaty of Saint Petersburg in February 1881.