In 1402 Oct 13, Johannes Corp was granted, by Henry IV, (In year 4 of his reign) a Royal licence to crenellate Dertemuth (Gommerock [or Paradise House or Kingswear Castle])

"Licence for John Corp of Dertemuth to crenellate a lodging his by the entrance of the port of the town for defence against the kings enemies.
quaddam hospitium juxta introitum portus vill de Dertemoth"

Granted at Westminster, by privy seal.

Licence for defence against the king's enemies. Clearly intended to be a serious fortification. Called a municipal licence by Coulson. Sometimes identified as an earlier building on or near the site of Kingswear castle or Paradise House, but the Gommerock identification seems more likely to me. The precussor to Dartmouth castle was built by John Hawley from 1388 but Gommerock also dates from this time, being the other end of the harbour chain. The chain was laid in 1400, so the licence either represents a 'topping out' of the fortification, or more probably, was applied for to give Corp some kudos. The much large fort at the other end of the chain, built by the more important John Hawley, was not given a licence. Corp seems to have indulged in some 'oneupmanship'.
Both Corp and Hawley were a leading seamen, ship owners and merchants in Dartmouth and served in official and unofficial (privateer) royal fleets. Both were actively concerned with the defence of Dartmouth. Corp served on a commision regarding the defence of Dartmouth in 1381. There is no question that the Gommerock building was defensive but this building did not require a licence and the licence presumably was granted to give additional kudos to John Corp.

Original source is

• Calendar of Patent Rolls (1402-5) p219

(In fact, the original source given is usually a transcription/translation of what are precious medieval documents not readily availably. It should be noted that these transcription/translations often date to the nineteenth or early twentieth centuries and that unwitting bias of transcribers may affect the translation. Care should also be taken to avoid giving modern meaning to the medieval use of certain stock words and terms. Licentia is best translated as 'freedom to' not 'permission'.)

Significant later source are;

• Coulson, C., 1995, 'Battlements and the Bourgeoisie: Municipal Status and the Apparatus of Urban Defence' in Church, Stephen (ed), Medieval Knighthood Vol. 5 (Boydell) p170n201, 189
  Higham, R. A., 1988, 'Devon Castles: an annotated list' Proceedings of the Devon Archaeological Society Vol46 p146
  Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol3 pt2 p421[wrongly identified as Dartmouth Castle]

John Corp (d.c. 1417)

John Corp (d.c. 1417), 1 Oct. 1399 Appointed Deputy Butler in all ports in Devon. Numerous royal appointments. M.P. for Dartmouth in 1411 and 1413.

Biographical source include;

• Roskell, J.S., Clark, Linda and Rawcliffe, Carole, 1992, The House of Commons 1386-1421 (History of Parliament Trust) Vol2 p663-4

More details about licences to crenellate can be found here.

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