The siege of Gongenyama (権ç¾山ã®æÂ¦ãÂÂ) occurred in 1510 during the Sengoku period of Japan's history. The daimyà  Uesugi Tomoyoshi (ä¸ÂæÂÂæÂÂè¯; died 1518) had a retainer Ueda Masamori (ä¸Âç°æÂ¿çÂÂ) who rebelled against him and laid siege to his . Masamori was defeated.