Peter Lely

Warts and all means the entire thing and not concealing any detail, and it derives from Oliver Cromwell, the Lord Protector of England in the 1650s.

Cromwell instructed the royalist painter Sir Peter Levy to paint his portrait, and as was usual at the time, Levy's style was to flatter the subject, showing them in the best possible light, with all blemishes removed.

Cromwell was known for being opposed to personal vanity, and he issued this instruction to Levy.

Lily did just that, and the portrait includes a mole above Cromwell's eye and a large wart below his lip.