> 16th century

OED2 gives Whilly the nod:

1597 Shakes. 2 Hen. IV, iii. ii. 338 (Qo.) The whores cald him mandrake.

Their previous citations are part of the glorious pattern of variations down the centuries:

1546 J. Heywood Prov. ii. vii. (1867) 71 Hop hoore, pipe theefe. 1595 in Maitl. Club Misc. I. 73 Ane ressavear of huiris and harlottis in her hous.