The Siege of Iwatsurugi was fought in the year of 1554. The siege was just one of a number of military actions that Shimazu Takahisa

Shimazu Takahisa

, the son of Shimazu Tadayoshi, was a daimyo during Japan's Sengoku period. He was the fifteenth head of the Shimazu clan.On 1526, Takahisa was adopted as the successor to Shimazu Katsuhisa and became head of the clan. He launched a series of campaigns to reclaim three provinces: Satsuma, Osumi,...

 had to take against his rebellious kokujin vassals.
Iwatsurugi yamashiro was located at the top of a hill and the only way to reach it was through narrow passes. During the siege Ijuin Tadaaki

Ijuin Tadaaki

Ijuin Tada'aki a retainer of the Japanese clan of Shimazu following the Sengoku period of the 16th century of Japan. Under Tada'aki, Ijuin clan would rise to the prominence as one of the most important retainer in the Shimazu clan....

, one of the Shimazu generals, used the tactic of "maneuvering five ships close in to the shore and shooting with firearms" onto the enemy garrison, a few of which were killed. The siege lasted a few weeks until the castle fell.