Green’s Dictionary of Slang

King Billy n.

also Billy
[King William IV of England (r.1830–7)]
(Aus.)

1. a generic term for any Aboriginal leader.

M. Clarke ‘King Billy’s Troubles: or Governmental Red-Tapeism’ in Australian Tales (1896) [Internet] ‘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.
[Aus]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.’.
[UK]Sporting Times 3 Jan. 5/5: King Billy [...] was told off to interview the missionary.
[Aus]‘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.’.
[Aus]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.
[Aus]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.

[Aus]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!
[Aus] (?) H. Lawson ‘Triangles of Life’ in Roderick (1972) 622: The meat had really been taken by the mangy, hairless, hide-covered skeleton of a starved kangaroo dog ‘belonging to King Billy’ [...] Billy (the royal one) said he believed his dog belong-it the devil.
[Aus]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.