The parliament.uk website describes the Serjeant at Arms as the official responsible for keeping order within the Commons part of the parliamentary estate.
The page describes various ceremonial duties that fall to the Serjeant, including processing with the House of Commons mace at the daily opening of the House, and the power to escort people from the Chamber when called upon by the Speaker. Historical powers of the role are also mentioned.
Does the role still have a functional purpose today, or are the duties purely ceremonial, as the link seems to suggest? When was the last time that the Serjeant was required to escort someone from the Chamber?