During the late Heian period, Saneyoshi, who were then minister of the left, owned a villa at the southwest foot of Mount Kinugasayama, and built therein a jibutsudo (the hall for the family's protective deity) called Tokudai-ji Temple.
平安時代末期、左大臣時代の実能が衣笠山の西南麓を所有した別邸を営み、その中に持仏堂を建て徳大寺（得大寺）と命名。