His wife's older sister Anshi became the wife of Emperor Murakami and gave birth to Imperial Prince Emperor Reizei, Imperial Prince Tamehira, and Emperor Enyu, and entrusted Takaakira as the chugudaibu (The chief administrator of the Empress's household).
また、妻の姉の安子は村上天皇の中宮であり、東宮（皇太子）冷泉天皇、為平親王、円融天皇を産み、高明は安子に信任され中宮大夫を兼ねた。