Born on 12 November 1683, he was the son of John Layer, a laceman, of Durham Yard, The Strand, London and Anne his wife.
Layer's uncle, finding himself in difficulties, offered to make over to his nephew the remains of his estate, in exchange for cash and an annuity.
In the end Layer was betrayed by two female friends and placed under arrest; he managed to escape, but was retaken after a chase the same evening and closely confined in the Tower of London.
Among papers found in Elizabeth Mason's possession was one entitled the Scheme, sworn to be in Layer's writing: it gave instructions for the proposed insurrection.
Layer and his counsel argued in his defence; but, after a trial of eighteen hours, the jury unanimously found a verdict of guilty.
There is an anecdote that Layer's head fell from the top of Temple Bar, where it had been placed, and was bought by a nonjuring attorney named Pearce; who resold it to Richard Rawlinson, the Jacobite antiquary.