The Imperial family struggled against the control of the Fujiwara clan, which almost exclusively monopolized the post of regent (Sesshō and Kampaku). Feudal conflicts over land, political power, and influence eventually culminated in the Genpei War (1180–1185). This was a national civil war between the two most powerful clans: the Taira and Minamoto clans. They fought for control over the declining Imperial Court in Kyoto. Each side had a large number of smaller allied clans. The Battle of Dan-no-Ura was a major naval battle between these clans on April 25, 1185. Minamoto had a fleet of 300 ships and Taira had 400 to 500 ships. It resulted in a decisive victory for the Minamoto clan and the destruction of the Taira clan. The end of the Genpei War brought the end of the Heian period and the beginning of the Kamakura period.