Since Emperor's maternal uncles, FUJIWARA no Michitaka, FUJIWARA no Michikane and FUJIWARA no Michinaga, took political power by turns under Emperor Ichijo's supervision and regulated Kokyu (a special part of the Imperial Palace in which empresses and princesses live), Emperor Sanjo was 36 years old when he was finally enthroned, having been the crown prince for 25 years, when he took over from Emperor Ichijo.
外舅にあたる藤原道隆・藤原道兼・藤原道長三兄弟が先後して政権を掌握し、それぞれ一条天皇のもとで後宮政策を布いたため、三条天皇は25年という長い東宮時代を経て、36歳でようやく一条帝の譲りを受けて即位。