Ogimachi became Emperor upon the death of Emperor Go-Nara. In 1560 Ogimachi was proclaimed emperor. The ceremonies of coronation were made possible because they were paid for by Mori Motonari and others.
The finances of the emperor and his court were greatly strained. The authority of the Imperial Court also began to fall, but this trend reversed after Oda Nobunaga entered Kyoto in a show of allegiance but which also indicated that the Emperor had the Oda clan's support. Frequently using the Emperor as a mediator when fighting enemies, Nobunaga worked to unify the disparate elements to Japan. However, by around 1573, Nobunaga began demanding the Emperor's abdication, but the Emperor refused.
Before political power was transferred to Toyotomi Hideyoshi, in order to take advantage of Ogimachi's authority, the power of the Imperial Family was increased. In this way, Hideyoshi and the Imperial Family entered into a mutually beneficial relationship.
In 1586, Emperor Ogimachi abdicated in favor of his grandson, Imperial Prince Katahito, who became the Emperor Go-Yozei. Ogimachi retired to the Sennōda Palace. On February 6, 1593, he died.