The Gatehouse website record of a licence to crenellate for Bampton Ham Court granted on 1315 May 3

In 1315 May 3, Adomarus de Valencia, Comes Pembroch (Aymer de Valence, Earl of Pembroke) was granted, by Edward II, (In year 8 of his reign) a Royal licence to crenellate Bampton (Bampton Ham Court)

Granted at Westminster. Grant by King.

Comments

Half brother of Henry III; an active diplomat for both Edward I and Edward II. This licence granted during a particularly active period of service to the King.

Original source is;

Lyte, H.C. Maxwell (ed), 1898, Calendar of Patent Rolls (1313-17) p. 278 online copy

(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 sources are;

Emery, Anthony, 2006, Greater Medieval Houses Vol. 3 (Cambridge) p. 211
Crossley, Alan (ed), 1996, 'Bampton and Weald: Manors and castle' VCH Oxfordshire Vol. 13 p. 22-30
King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 2 p. 389n2
Turner, T.H. and Parker, J.H., 1859, Some account of Domestic Architecture in England (Oxford) Vol. 3 part 2 p. 407 online copy

Valence, Aymer de, eleventh earl of Pembroke (d. 1324)

Valence, Aymer de, eleventh earl of Pembroke (d. 1324), magnate, was the son of William de Valence (d. 1296), the half-brother of Henry III, and therefore closely related to both the kings of England who ruled during his lifetime; through his mother, William de Valence's wife, Joan de Munchensi (d. 1307), he was descended from the Marshal earls of Pembroke. In April 1314 Pembroke was appointed as the king's lieutenant in Scotland, in advance of the campaign to relieve Stirling which culminated in the disastrous English defeat at Bannockburn on 24 June. Pembroke was close to the king, and intervened to lead him away from the battle to safety at Dunbar and thence to Berwick. On 2 January 1315 Pembroke attended Gaveston's reburial at Langley; in May and June he visited Paris on behalf of Edward II to obtain confirmation from the new French king, Louis X, of previous Anglo-French agreements; between July and October 1315 he organized the defence of the northern borders from Scottish attack. In February 1316 he deputized for the king at the opening of the Lincoln parliament, at which the earl of Lancaster was nominated as the king's chief councillor, and was a member of the committee appointed to consider reform of the realm and the royal household. In July he helped to end the resistance of Bristol to royal authority. (Phillips)

Biographical source include;

J. R. S. Phillips, 2004, ‘Valence, Aymer de, eleventh earl of Pembroke (d. 1324)’ Oxford Dictionary of National Biography (Oxford University Press) online copy (subscription may be needed)