To this chair James I annexed, as endowment, the rectory of Somersham in Huntingdonshire Collins is said to have lectured for 34 years, twice a week, constantly covering fresh material.
At the time of the First English Civil War he was royalist, and in 1643 Edward Montagu, 2nd Earl of Manchester and other commissioners ejected him from the rectory of Fen Ditton.
On 9 January 1645 he was deprived of the provostship of King's College by order of parliament, in a visitation of the university by the Earl of Manchester.
It appears that he was allowed to retain the sinecure rectory of Milton, and his Regius chair, but the living of Somersham was taken from it.
He lived a retired life in a house in St. Radegund's Lane, opposite Jesus College, Cambridge.