mid-13c., etymologically "person who manages a chamber or chambers," but by the time the word reached English it had evolved to describe an important royal officer of various duties, such as "one who attends a king or person of high rank in his or her private chamber," and especially "keeper of the treasure-chamber;" from Old French chamberlenc "chamberlain, steward, treasurer" (Modern French chambellan), from a Germanic source (perhaps Frankish *kamerling; compare Old High German chamarling, German Kämmerling), from Latin camera "chamber, room" (see camera) + Germanic diminutive suffix -ling. As "chief financial officer of the king's household" from mid-15c.
