Green’s Dictionary of Slang

a sovereign.

1887		W.E. Henley Villon’s Straight Tip n.p.: Your merry goblins soon stravag: Boose and the blowens cop the lot [F&H].
1898		W. Pett Ridge Mord Em’ly 285: I’ve spent those little goblins, I ’ave.
1906		E. Dyson Fact’ry ’Ands 214: He was goin’ under er operation yes’day ter recover the lost goblin.
1925		Wodehouse Carry on, Jeeves 89: You don’t think I’m going to chuck a future like this for anything under five hundred o’ goblins a year – what?