Born into a prominent legal family, Croke owed his unusual first name to his paternal grandmother’s family, the Untons of Chequers in Buckinghamshire. His father served as Speaker of the Commons in 1601, and became a justice of King’s Bench six years later.21 HP Commons, 1558-1603, i. 676-8. Croke himself was admitted without fine to the Inner Temple at about the age of 15, during the treasurership of his uncle George Croke†. He inherited only £40 and an annuity of £20 when his father died in 1620,22 Croke, i. 483. but his marriage brought him property at Marston in Oxfordshire worth £50 p.a., where he rebuilt the house.23 Parochial Colls. 203; VCH Oxon. v. 215, 217. Having obtained from the 3rd earl of Pembroke the sub-stewardship of the university, the principal law officer of the institution, he maintained a house in Oxford.24 M. Toynbee and P. Young, Strangers in Oxford, 138; VCH Oxon. iv. 97.
Croke was returned for Wallingford to the 1626 Parliament, although his connection with the borough is unknown. His only committee appointment was for a private land bill (1 Mar.) and on 5 Apr. he was excused absence from the House, being sick. On 28 Apr., on the information of John Saunders*, he was granted privilege against Sir Thomas Whorwood, a litigious Oxfordshire neighbour who had been examining witnesses in Chancery ‘concerning the inheritance of Mr. Unton Croke’. Croke himself told the Commons that Whorwood had ‘reviled him’, by accusing him of becoming ‘a Member of this House by bribery and corruption’. Whorwood was ordered to be sent for ‘to answer his contempt to the House’ and ‘the said words’, but no further proceedings are recorded and Croke left no further traces on the records of the Parliament.25 Procs. 1626, ii. 158, 431; iii. 89.
There is no evidence that Croke sought re-election in 1628, although he was returned again for Wallingford to the Short Parliament. He seems to have kept a low profile during the Civil War, when he was appointed to one royalist commission, but apparently escaped sequestration by the Roundheads. However, his sons were active parliamentarians. Indeed, one of them, Unton†, became an officer in Cromwell’s army, and perhaps as a consequence, Croke was created a serjeant-at-law by the Protector, although the appointment lapsed at the Restoration. Croke’s elder son Richard sat for Oxford in the Protectorate Parliaments and in 1661. Croke died on 28 Jan. 1671, aged 77, and was buried at Marston. No will has been found.26 Oxford DNB; Parochial Colls. 203.