Namamugi Incident
Nagayuki became a prominent official in the Tokugawa shogunate, with the positions of "wakadoshiyori" in 1862; "rōjū-kaku" in 1862-1863 and in 1865; and "rōjū" in 1865-1866 and in 1866-1868. During these periods, he was primarily involved with foreign affairs, and was one of the senior Japanese officials during negotiations with Great Britain over reparations following the Namamugi Incident.