Tombs of Empress Dowager Cixi (left) and Ci'an

Empress Dowager Cixi, or Empress Dowager Tzu-hsi (29 November 1835 – 15 November 1908), of the Manchu Yehenara clan, was a powerful and charismatic woman who unofficially but effectively controlled the Manchu Qing Dynasty in China for 47 years, from 1861 to her death in 1908.

http://en.wikipedia.org/wiki/Empress_Dowager_Cixi

Empress Dowager Ci'an (20 August 1837 – 8 April 1881), popularly known in China as the East Empress Dowager, and officially known posthumously as Empress Xiao Zhen Xian, was the second Empress Consort of the Xianfeng Emperor (b. 1831 – d.1861) of the Manchu Qing Dynasty in China, and then Empress Dowager after 1861. She is known for being co-de facto ruler of China with Empress Dowager Cixi for 20 years.