Riley studied painting under Isaac Fuller and Gerard Soest, and from the latter learnt a forcible, straightforward style of portraiture which rendered his portraits noteworthy.
Riley did not attain much eminence until the death of Sir Peter Lely, when courtier and royal official Thomas Chiffinch sat for him, and was so much pleased with his portrait that he showed it to the king.
She was a "necessary woman" at court whose duties included emptying and scouring chamber pots and cleaning the royal apartments.
Two other, smaller, portraits of servants are Katherine Elliot (also Royal Collection) and A Scullion in the Christ Church Picture Gallery, Oxford.
[4] He was assisted in painting (at least) his draperies and accessories by John Closterman, who finished several of Riley's pictures after his death.