during the edo period, yokosuka "tenryō" territory was controlled directly by the tokugawa shogunate, but administered through various "hatamoto". due to its strategic location at the entrance to tokyo bay, the shogunate established the post of uraga "bugyō" in 1720, and all shipping into the bay was required to stop for inspection. as concerns over the increasing number of incursions by foreign vessels and attempts to end japan's self-imposed national seclusion policy, the shogunate established a number of coastal artillery batteries around yokosuka, including an outpost at ōtsu in 1842. however, despite these efforts, in 1853, united states naval commodore matthew perry arrived in tokyo bay with his fleet of black ships and came ashore at kurihama, in southern yokosuka, leading to the opening of diplomatic and trade relations between japan and the united states. the "kanrin maru" sailed from yokosuka in 1860 with the first japanese diplomatic embassy to the united states in 1860.