Green’s Dictionary of Slang

1. a generic term for any Aboriginal leader.

a.1881		M. Clarke ‘King Billy’s Troubles: or Governmental Red-Tapeism’ in Australian Tales (1896) 🌐 ‘Budgeree, climb tree’ says King Billy, turning his dilapidations towards us with the elegant simplicity of the savage [...] His Majesty King William the First was the chieftain of the Great Glimmera blacks.
1887		Bulletin (Sydney) 5 Nov. 9/2: King Billy was a monarch of some importance in those days, and experienced little difficulty on obtaining enough alcoholic stimulant to keep himself well ‘in soak.’.
1891		Sporting Times 3 Jan. 5/5: King Billy [...] was told off to interview the missionary.
1895		‘Banjo’ Paterson ‘Johnson’s Antidote’ in Man from Snowy River (1902) 143: King Billy, of the Mooki, chieftain of the flour-bag head, / Told him, ‘Spos’n snake bite pfeller, pfeller mostly drop down dead.’.
1900		Bulletin (Sydney) 27 Jan. 14/3: Well, I met King Billy of Bungaboola out-back t’other day – a civilised King Billy, an educated King Billy, oh! a wealthy King Billy – with a tray buggy, a passable horse, and a seductive cattle-pup, ‘just travellin’. [...] I looked in perplexity to where Mrs. Billy was standing with gleaming teeth, an indubitable black-gin.
1914		Bulletin (Sydney) 10 Sept. 24/4: In Swanston-street Jacky Jacky boarded the tram. Jacky was about 30, and of royal descent, being grandson of King Billy, of the tribe of Binbalingee. But his royal house had fallen on evil days, and Big Amy was garbed in a pair of old pants.

2. any Aboriginal singled out from the rest.

1897		H. Lawson ‘A Little Mistake’ in Roderick (1967–9) I 318: There’s ould King Billy wid niver a stitch / For a month — may the drought cremate him!
1902		‘Dads Wayback’ in Sun. Times (Sydney) 6 July 13/7: ‘Our blackfellers uster court very sudden, but it answered fust rate, an’ ther lawyers never scored off King Billy in the Divorce Court’.
1912		Bulletin (Sydney) 1 Aug. 16/1: King Billy’s lady, who frequently puts through her ‘interesting event’ job in a few hours, is by no means a lone circumstance.
2012		(con. 1943) G.S. Manson Coorparoo Blues [ebook] [H]e’d picked up a few pointers from King Billy, the tracker who went out with him to bring in Myalls [...] His real name was baccy Billy Murri.