Honkokuji was founded by Nichiro, a direct disciple of Nichiren, and rose to national prominence in 1568 when Ashikaga Yoshiaki — the last Muromachi shogun, installed by Oda Nobunaga — used it as his provisional palace (Rokujo Gosho). In January 1569, the Mitsutani Trio (Miyoshi Sanninshu) and Saito Tatsuoki launched a surprise attack on Yoshiaki at Honkokuji in what became known as the Honkokuji Incident (Honkokuji no hen).