In 1853, Commodore Matthew C. Perry of the United States Navy entered the port of Yokohama near Edo (Tokyo) with an intimidating fleet of steam warships. His objective was to open Japan’s doors to trade after nearly two centuries of restricted contact with the outside world. Perry’s visit prompted the Edo shogunate to reconsider, with feudal lords in the area, the method of coastal protection and to order the construction of forts around present-day Tokyo Bay. This okatame (coastal defense) map depicts the system of defense as it was in 1852 and provides information about the foreigners who had since arrived. The gridded chart pasted on the bottom of the map contains the hereditary crests and decorative staffs of the samurai (feudal lords) who were in charge of protecting the coastal areas under their administrative control. The map is oriented with north pointing to the lower left, positioning the capital city of Edo in the lower-left corner. The shogunate initially had planned to build eleven forts but managed to complete only five. The forts and their measurements also are shown on the lower left corner, standing between the foreign fleets and the capital city.