Bentley witnessed deeds at his home town, Plymouth, from 1396 onwards, and he acted as a feoffee of property in Sutton Vautort and Sutton Priour, the townships which joined to form the borough.
Bentley acted as executor of the will of Walter Crocker, a sometime mayor of Plymouth, and was himself elected mayor on no fewer than four occasions. On 27 Aug. 1400, during his first known mayoralty, Henry IV’s council issued orders for his arrest and for the confiscation of his goods and those of Richard Spicer alias Newport of Plymouth which were in his keeping. Bentley had previously acknowledged in the court of admiralty that he was answerable for the sum of nearly 3,000 marks for merchandise taken at sea by Spicer. However, despite his admission before the King and the Council that he still had some of the goods in his custody, they had since been informed that it was his intention to flee the country and dispose of the spoils abroad. The outcome of Bentley’s second appearance before the Council is not known, but his arrest was ordered again on 4 Dec., following a complaint by Martin Ferrers† that when he had tried to carry out a commission of array at Sutton Vautort, Bentley and others had assaulted him, besieged him in a house at Sutton Priour, and set free certain Bretons whom he had arrested under letters of marque. It seems, however, that Ferrers’s charges were exaggerated: before the end of the month the Council was reliably informed that the allegations were untrue, and that if indictments were brought it would tend to the ruin of the commonalty of Plymouth. The parties were ordered to present themselves in person at the forthcoming Parliament where the case would be judged.
Bentley’s activities at sea, not all above suspicion of piracy, continued as before. In 1402 he was in possession of a cargo taken from certain Spanish merchants, and was ordered to retain it intact, under a penalty of £1,000. On 6 Aug. that year, described as ‘of Devon, esquire’, he stood surety at the Exchequer for the ex-admiral, who was now duke of York, when he was granted custody of the estates of his late father, Edmund of Langley. And it was also as ‘esquire’ that on 26 Aug. 1403 Bentley procured royal letters of protection for one year, as being about to put to sea on the King’s service to execute a commission (issued on the same day) to defend the wine fleet from attack by Breton vessels on its voyage from Plymouth to Bordeaux. That autumn, following the capture of several Spanish ships by a fleet under the command of Thomas Norton of Bristol and John Hawley I of Dartmouth, Bentley undertook to levy all the freight found in Plymouth, Kingswear, Saltash, Fowey and East Looe which certain foreign merchants claimed had been seized in breach of the truce.
Bentley is not known to have had any connexion with Tavistock, the borough which he represented in the Parliament of 1420, but since he was engaged in the tin trade, he probably had dealings at the stannary there. At the time of his election he was serving as customer in Plymouth and Fowey. In April 1423 he purchased from William Soper, the keeper of the King’s ships, the royal ballinger called George, which vessel, built ‘ad modum unius galee’; at a cost of more than £229, he secured for a mere £20. He is not recorded after his replacement as customer in November of that year.