Who was the emperor while Prince Sanjō Sanetomi was an Imperial court noble? 
Sanjō Sanetomi: Prince Sanjō Sanetomi (三条 実美 , 13 March 1837 – 18 February 1891) was an Imperial court noble and statesman at the time of the Meiji Restoration. Meiji Restoration: The Meiji Restoration (明治維新 , Meiji Ishin ) , also known as the "Meiji Ishin", "Renovation", "Revolution", "Reform", or "Renewal", was an event that restored practical imperial rule to Japan in 1868 under Emperor Meiji.
Emperor Meiji