The Siege of Tachibanayama occurred in Tenshō 11 (1583) on Mount Tachibana in the Mugi District of Mino Province.  The conflict was waged between the Endō clan (Endō Yoshitaka and Endō Tanemoto) and the allied forces of the Satō (Satō Hidekata) and Mori (Mori Nagayoshi) clans.

In 1582, after Akechi Mitsuhide was defeated by Hashiba Hideyoshi at the Battle of Yamazaki, Oda Nobutaka, the lord of Gifu Castle in Mino, came into conflict with Hideyoshi.  Many of the bushō in the northern and eastern portions of Mino pledged allegiance to Hideyoshi, but Endō Yoshitaka and Endō Tanemoto of the Gujō District aligned with Nobutaka.

In the first month of 1583, troops in the Mugi District set-up camps in Suhara and Horado, severing the route between Gujō and Gifu.  After learning of these developments, 300 mounted soldiers (or, according to another source, 2,000 soldiers) overran the camps and then positioned troops on Mount Tachibana for defense.  On 1/8 of Tenshō 11 (1583), Satō Hidekata (the lord of Kōzuchi Castle in the Mugi District) allied with Mori Nagayoshi (the lord of Kaneyama Castle in the Kani District) and, under orders from Hideyoshi, encircled Mount Tachibana.  Yoshitaka dispatched a secret messenger to request reinforcements from Nobutaka at Gifu Castle.  Nobutaka praised their defensive efforts and promised to send a reinforcement army but these forces did not easily arrive.

In the second month, the supply of provisions ceased and the defenders were relegated to grilling and eating bear skin used for horse tack.  Residents from Kio and Mikkaichi filled saké barrels with rice to appear as saké and brought them on mountain roads to the camp, provided temporary relief, but as the siege continued to tighten, those at Tachibanayama resorted to acts such as roasting bear skin for food.  For a while, some considered charging out of the castle, seeking an honorable death in battle rather than starve.  A messenger sent by Satō Hidekata then informed them that Shibata Katsuie had died at the Battle of Shizugatake in the fourth month of 1583 and Oda Nobutaka had surrendered after a siege of Gifu Castle.  The men subsequently decided to surrender upon which they tendered Ishigami Hyōgo and Endō Toshiemon as hostages to Hideyoshi and, after the two armies settled at Hanno, the Endō clan came under the command of Hideyoshi.

Owing to this battle, Satō Hidekata became a retainer of Hideyoshi and acquired control over a majority of the Mugi District (totaling 25,000 koku).  After the conduct of land surveys by the Toyotomi administration, the landholdings of Endō Yoshitaka and the others were seized while Yoshitaka was transferred to Obara the Kamo District with a fief of 7,500 koku and Tanemoto to Inuji in the same district with a fief of 5,500 koku.