The name Serjeant-at-Arms derives from the latin serviens or servant.
In the United Kingdom in medieval times, monarchs used people who provided services like the provision of arrows, fodder and waiting upon the King at table who were called serjeanties. Later people who were permanently retained by the Sovereign became known more particularly as serjeants. These officers were required to be in immediate attendance on the Monarch's person to arrest traitors and other offenders. In medieval times:
The activities of the King's Serjeant-at-Arms included collecting loans and, impressing men and ships, serving on local administration and in all sorts of ways interfering with local administration and justice.
By 1415, a specific officer was appointed 'AS SERJEANT-AT-ARMS FOR THE COMMONS' (Nicholas Maundit) to be attendant upon the House of Commons or the Speaker.
When Henry VIII left the Palace of Westminster, two Serjeants, though still officers of the court, continued to attend upon the Parliament - one serving the House of Lords and the other the House of Commons.
Today the Common's Serjeant is warranted to attend upon Her Majesty's person when there is no Parliament; and at-the time of every Parliament to attend upon the Speaker of the House of Commons.
In the Australian Parliament the Serjeant is a career officer of the Department of the House of Representatives.
The Serjeant's raison d'etre is the same in Australia as in the United Kingdom and
the classic explanation is that given by Chief Justice Lord Coleridge in 1884 when he pointed out that, "The Houses of Parliament cannot act by themselves in a body; they must act by officers; and the Serjeant-at Arms is the legal and recognised officer of the House of Commons (Representatives) to execute its orders."
The traditional responsibilities of the Serjeant as attendant upon the Speaker expanded more broadly to being attendant on the House. In the House of Commons, the role of the Serjeant extended to include being the Housekeeper for the Commons. The Serjeant in the House of Representatives has important responsibilities for Members' accommodation and furnishing.