Green’s Dictionary of Slang

1. (also bully of the blade) a bully, a thug.

1659		Catterpillers of this Nation Anatomized 2: The Hector or Knight of the Blade, with his Rum-Mort or Doxie.
c.1698		B.E. Dict. Canting Crew n.p.: Knight of the Blade, c. a Hector or Bully.
1700		T. Brown Amusements Serious and Comical in Works (1744) III 61: Whereupon a bully of the blade came strutting up to my very nose, in such a fury.
1725		New Canting Dict.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Knight of the blade. A bully.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1785].

2. a wandering villain, posing as a soldier and living on his wits.

1663		J. Wilson Cheats IV i: Who made you a captain? [...] Did not I pick thee up at a threepenny ordinary, brought you into gentlemen’s company, dub’d you knight of the blade, taught you the method of making new plots [...] I know that you were never a corporal in all your life.
1785		Grose Classical Dict. of the Vulgar Tongue.
c.1790		‘Peter Pindar’ ‘Complimentary Epistle to James Bruce’ Works (1794) II 491: Knights of the blade, One time so busy in the dubbing trade.
1809		G. Andrewes Dict. Sl. and Cant n.p.: knight of the blade a hectoring sham captain, a bully.
1821		Flash Dict. [as cit. 1809].
1835		G. Kent Modern Flash Dict. 20: Knight of the blade – a bullying sham captain, a braggadocia.
1848		Flash Dict. in Sinks of London Laid Open [as cit. 1835].

3. (Aus., also knight of the blades) a shearer.

1896		Worker (Sydney) 5 Sept. 3/4: If the ‘knights of the blades’ and their comrades will resolve to sink all minor issues [...] Unionism must soon flourish and become all powerful throughout Australia.
1898		Worker (Sydney) 26 Feb. 7/2: As ‘Knights of the Blade’ we may not be as swift as Power or Mick the Ringer, but we are all there from start to finish.