Green’s Dictionary of Slang

a euph. for buggered adj.¹ ; thus I’ll be beggared if...

1841		‘The Racehorse’ in Gentleman Steeple-Chaser 6: Oh says the donkey hot and funky, / I’m beggared if I an’t off again.
1858		Hereford Times 23 Jan. 6/6: That’s very good, sir; but I’ll be beggared [...] if something isn’t come to my legs.
1866		Wild Boys of London I 117/1: ‘Beggared!’ repeated Hallelujah Jack to himself, shaking his fist at the two conspirators. ‘Beggared if they shall be.’.
1898		Lincs. Echo 1 Nov. 4/5: I’ll be beggared, but I’ll not sleep under her roof [...] I’d rather face a miners’ strike" Well, I’m beggared!
1903		J. Furphy Such is Life 133: You ain’t a bad hand at sleepin’—no, I’m beggared if you are. I bin bellerin’ at you for two hours, dash near.
1975		W. Trevor Angels at the Ritz 247: ‘Well, I’m beggared,’ remarked Mr Uprichard.