The first ship known to follow this practice was the Nippon Maru, flagship of daimyō Toyotomi Hideyoshi's 16th century fleet.
Several theories purport to explain this practice: Today many commercial and private ships are still named using this convention.
Two ship names were submitted by the Minister of the Navy to the Lord Chamberlain who then presented the choices to the Emperor.
On 23 April 1905, Naval Minister Gonbee Yamamoto reported to the throne about a new ship naming standard.
US Naval Intelligence built up knowledge of enemy ships through photographic reconnaissance, interrogation of prisoners, and signal interception.
For example, a prisoner of war after the battle of Midway reported the existence of an aircraft carrier named Hayataka.
(Shinano had begun construction as a Yamato-class battleship and was thus named for a province, before being converted into an aircraft carrier following the Battle of Midway.)