Career
He was the last head of the Fukui Domain in Echizen Province. Mochiaki first ruled the Itoigawa Domain. He was adopted by Matsudaira Yoshinaga.
When Yoshinaga gave up his title and power, Mochiaki became the head of the Fukui Domain.
After the daimyo were abolished, he was made an Imperial governor of Fukui. He was created a count.
And he was promoted to marquis in 1888.