Croft was born 18 May 1603 at Great Milton, Oxfordshire, his mother being then on a journey to London, the third son of Sir Herbert Croft and his wife Mary, daughter of Sir Anthony Bourne of Holt Castle. He married, before 8 April 1645, Anne Browne, the only daughter of the Very Review Doctor Jonathan Browne and Anne Barne Lovelace.
Her half-brothers were Richard Lovelace (1618–1657) an English poet in the seventeenth century and Francis Lovelace (1621–1675), who was the second governor of the New York colony appointed by the Duke of York and of Albany (later King James II & VII. Becoming disillusioned with court life he returned to his Hereford see. Despite his youthful adherence to that faith, he was noted for exceptional severity towards Roman Catholics, especially during the Popish Plot. Number doubt for this reason, at the outset the Plot Titus Oates claimed that the Jesuits had marked Croft for assassination: why the Jesuits should be anxious to kill a man who lacked any influence at Court was a question which probably did not occur to Oates, who was a stranger to the Court and to polite society.
