What is the surname of the Dowager Countess's butler?

The Dowager Countess's butler is Mr Septimus Spratt, so his surname is Spratt. He serves Violet Crawley, the formidable Dowager Countess, and appears as part of her highly formal household staff.

Spratt is introduced as a precise, status-conscious butler whose loyalty to Violet is mixed with a strong sense of professional pride. His scenes often contrast his strict interpretation of domestic service with the more relaxed or modern attitudes developing elsewhere at Downton. He is particularly protective of Violet's routines and reputation.

A memorable subplot reveals that Spratt secretly writes an advice column under the name Miss Cassandra. The discovery surprises Violet and gives the character a comic dimension beyond his stern public manner. Spratt is easy to confuse with Charles Carson, Downton's principal butler, or Thomas Barrow, who later takes on the butler's role at the abbey. Neither is Violet's personal butler: that position belongs to Spratt.