legation (n.)

c. 1400, "mission of a deputy or envoy," from Old French legation "embassy, mission" and directly from Latin legationem (nominative legatio) "the office of an ambassador," noun of action from past participle stem of legare "send as a deputy" (see legate). From c. 1600 as "body of deputies sent, representatives," 1832 as "official residence of a diplomat."