Myrmidons, n. — Green’s Dictionary of Slang

Myrmidons n.

[‘Myrmidon [...] a member of a warlike people inhabiting ancient Thessaly, whom Achilles led to the siege of Troy’ OED]

a constable’s assistants.

c.1698		B.E. Dict. Canting Crew n.p.: Myrmidons c. the Constable’s Attendants, or those whom he commands (in the King’s Name) to Aid and assist him, also the Watchmen.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1790		‘Bumper Allnight. Esquire’ Honest Fellow 36: When a set of young fellows, the sons of delight, / Are assembled to spend in play-spouting the night / [...] / Let your ill-looking mormidons push themseves in.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1901		Sydney Sportsman (Surry Hills, NSW) 27 Feb. 1/6: [H]is myrmidons are wakeful / And get palm oil from the fakes.