Crompton inherited a leasehold at Cresswell, near Stafford, but does not appear to have been closely related to the Staffordshire gentry family seated at Stone.
At James I’s accession Crompton was appointed advocate-general, and knighted a month later. He was present at the Hampton Court Conference in January 1604, and in the same year edited Ecclesiae Anglicanae by Richard Cosin†, which he dedicated to the new king.
In the second session Crompton’s eight committee appointments included those to consider bills against married dons and cathedral clergy (25 Jan. 1606), against pluralities and non-residence (5 Mar.), for the restoration of deprived ministers (7 Mar.), and for Oriel College, Oxford (18 March).
Crompton drew up his will on 27 Jan. 1609, acknowledging the blessings of God which had brought him ‘even from nothing almost to that which I now have’. He desired that his debts might be ‘truly and honestly paid that I be not scandalized when I am dead’.
