Green’s Dictionary of Slang

1. (Aus./UK) a shilling [play on bob n.³ (2)].

1856		Mons. Merlin 18 Oct. 6/2: Numismatics seem to afford an unbounded range for the exercise of slang [...] Why should shillings be universally baptised ‘Roberts?’—and four-penny pieces ‘Joeys?’—or six-pences indiscriminately christened by the female title of ‘Tizzy?’.
1860		Bell’s Life in Sydney 28 Jan. 3/4: His Worship most politely offered blue-eyed Mary the alternative of [...] handing over forty ‘Roberts’.
1885		Bulletin (Sydney) 12 Sept. 10/2: [A] Salvation soldier borrowed a shilling to give to a fallen brother, in order that he might procure a bed. The latter, however, refused to take it, and the soldier, not wishing to return the ‘Robert,’ went down on his knees in the street and asked God to move him in what direction to spend it.
1886		Sporting Times 27 Mar. 1/1: He ‘blewed’ his last solitary ‘Roberto’.
1895		Riverina Recorder (Moulamein, NSW) 20 Mar. 2/7: [Y]ou can only get twenties to one about tbe Balranald Handicap [...] at that price it is only taken in ‘Roberts’.
1910		‘Doss Chiderdoss’ ‘The “Two Bob” Novel’ Sporting Times 30 Apr. 1/3: If democracy springs two Robertos to buy / A new novel, that novel must be / A good story.
1913		Truth (Sydney) 20 Apr. 10/3: Sometimes it’s a humble robert, / Mostly it are half a crown.

2. a police officer, usu. male; thus Roberts’ bungalow, a police station [elaboration of bobby n.¹ (1)].

1861		Bell’s Life in Sydney 16 Mar. 3/3: [He] gave the astonished Bobby a ‘regular buster’ [...] In the melée ‘Robert’s’ whiskers suffered severely.
1870		London Figaro 18 Nov. n.p.: That intolerable nuisance, the ‘British Peeler’ – who is always poking his nose where he is not wanted, and is never to be found when he is – is, after all, a sensitive creature. The blood of the roberts is at length aroused [F&H].
1884		Ally Sloper’s Half Holiday 7 June 47/2: To others Samuel Hardstaff is a peeler, a reeler, a copper, a Bobby, a Robert, an unboiled lobster, or a slop, but to cook he is Mr Policeman.
1885		Bulletin (Sydney) 9 May 14/3: Then, to the utter disgust of the crowd [...] a charitable ‘Robert,’ who had come on the scene when called for, […] stepped forward and ran him into the lock-up, money and all.
1895		Coburg Leader (Vic.) 13 Apr. 4/4: One of our councillors is going [to the Carnival] as a native cat. Another is going as a Robert (Policeman).
1899		J. Flynt Tramping with Tramps 231: But look out for the Robert and the Dee [the policeman and the detective].
1904		Sydney Sportsman (Surry Hills, NSW) 30 Nov. 4/1: [T]he cronk toteman, the palmist, the hooftist, the clairvoyant, the milk adulterator, and all the scounrelly, thieving gang [...] industriously ply their business and rake in the nimble coin While Robert sleeps.
1907		D. Stewart Shadows of the Night in Illus. Police News 9 Nov. 12/1: Ikey Coyle had closed the inn doors [and] tipped fees to the Robert on his beat.
1909		‘A “Push” Story’ in Bulletin (Sydney) 2 Sept. 17/1: ‘We got lively on our leather ’n’ 'twasn’t long before a ’ot chorus wuz ’ummin’round th’ Roberts’bungalow’.
1919		C. Hamilton William – An Englishman (1999) 68: ‘Let me go,’ she cried, wriggling in his grasp as she had wriggled aforetime in the hands of a London policeman, and kicking him deftly on the shins as she had been wont to kick Robert on his.
1930		‘Leslie Charteris’ Enter the Saint 41: Send one of your beauty chorus out for a Robert and give me in charge, if you like.
1959		I. & P. Opie Lore and Lang. of Schoolchildren (1977) 395: Nicknames current among boys [...] Robert, Rozzer.