The Gatehouse website record of a licence to crenellate for Penrhyn Castle granted on 1438 May 10

Henricus Dei gracia rex Angliae et Francia et dominus Hibernie Omnibus Ballivis et fidelibus suis ad quos presentes litterae prevenerint salutem. Sciatis quod nos pro finem tribus Solidos et quatour denarios nobis pro Johan pykmere et Johannam uxorem ejus similiter dedimus et concessimus eisdem Johani et Johannam licentiam pro nobis et heredibus nostris quod ipse consturere et consumare possent quendam turriculus in mansio suo apud Penryn in Villa de Greivorion cum parvo batellamento supra cacumen turriculi praedictem. Ita quod nec praesenti Johannes et Johanna neq heredes suam Johanna occasionamentum in aliquo seu gravent' pro constuiccoe et batallamento turriculi praedicti sine occasione vel impedimento nostri vel heredum nostrorum Justico Escaetorum aut aliorum ballivorum seu ministrorum nostrorum quorumcumque. In cujus sei testmonicus has literas nostras fieri fecimus patentes. Teste me ipso apud caernx. Die maij anno regni nostro sextodecimo
per billam signata locum fenentis
justico Northwall signat.

(expanded from the original abbreviated latin by the author of the below translation and by Philip Davis)

Henry by the grace of God King of England and of France and Lord of Ireland - To all his Bailiffs and faithful to whom these presents shall come Greeting. Know ye that we in consideration of a fine of three shillings and four pence paid to us by John Pykine and Joan his wife have given and granted to the said Joan and Joan licence for us and our Heirs that they may construct and complete one small Tower in their Manor at Penryn in the Ville of Greivorion with a little battlement on the top of the said tower so that neither the said John and Joan nor the Hiers of the said Joan shall molest or be disturbed by any one by the construction and battlement of the said tower without the let or hindereance of us or out Heirs Justices Escheator Sheriff's Bailiffs or any other of our Ministers whomsoever_ In Witness whereof we have caused these our letters to be made patent Witness ourself at Caernarvon the tenth day of May in the sixteenth year of our reign_
By Bill sealed with the Seal of the Deputy Justice of North wales_ (anonymous translation, in a ?18th or 19th century hand, with slight later corrections, held with the original deed)

Henry by the grace of God King of England and of France and Lord of Ireland - To all his Bailiffs and faithful to whom receive these presents letters Greeting. Know that, for a payment of three shillings and 4 pence paid to us by John Pykmere and also his wife Joan, we have given and granted freedom from ourself and our heirs that they may build and complete a tower in their manor of Penryhn in the township of Goronwy with small battlements on top of the said tower. So that neither the present John and Joan nor the hiers of the said Joan be in any way molested for the building of battlements on the said tower (they shall hold it) without let or hindrance from ourself or our hiers, justices, Escheators or any other bailiffs or ministers of ours whomsoever. (Translation by Philip Davis - please do send me a better translation)

Comments

The author of the translation held with the original letter knew Latin but was not a scholar of medieval court Latin and his copy of the Latin and his translation are both wanting.

This licence is quite different in detail from the usual licence, presumably because it was written by the officers of the Justice of North Wales, rather than the Westminster Chancery clerks. This is presumably also the reason a copy was not made into the the Westminster Rolls and the reason it is not calendared. The mention of a payment (finem is usually translated as fine but did not have, in any way, the sense of being a punishment) is unusual but 3/4d (a quarter of a Marc about two weeks wages for a modestly skilled worker) is not large and is the smallest of know fees charged)

Penryhn was supposedly in the hands of the son of Gwilym ap Griffith and his second wife Joan, daughter of Sir William Stanley of Hooton, Cheshire after the death of Gwilym in 1431. That son, also Gwilym, was born about 1420 and may, therefore, still been under age in 1438. Pykmere appears to be Joan's new husband. Was the manor house in Penrhyn Joan's Dower house? Was this licence more about establishing this as a home for John and Joan secure from interference by Gwilym when he came of age?

Original source is;

U.C.N.W Bangor, Penrhyn MSS. 20-22. The original letter with seal and a copy and translation.

(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'.)

In 1440 John Pykmere was described as 'a diligent intermediary between the king and his people in North Wales' and was pardoned for a recognizance of £200 so he must have been fairly wealthy. Pykmere seems to be a Cheshire place-name so, presumably, John was an English merchant in Caernarfon.

For Joan to be so prominently mentioned and for heirs to be specified it is clear she was of importance. In this context the only reasonable identification is that she was Joan the widow of Gwilym ap Gruffudd.

According to http://www.penrose.org/getperson.php?personID=I40628&tree=penrose
Jonet Stanlet (abt 1380 - 1466)
Jonet is the daughter of William Stanley (abt 1348-bef 1428) and Margery de Hooton (abt 1352-1430). She had 2 brothers, William and John. She had 3 husbands: Robert Paris, Judge (m. abt 1397), Gwilym ap Gryffydd (m. abt 1400) and John Pikine.
Penrose sources are:
S R Meyrick, 1846, Heraldic Visitation of Wales Vol 2 p. 89 (Footnote 1) online copy
J E Griffith, 1914, Pedigrees of Anglesey & Caernarvonshire Families pp. 106, 185 -- Griffith-Shows all his children as of the 2nd wife except Tudur Vychan of Penmynydd.

Similar at http://geneagraphie.com/getperson.php?personID=I116287&tree=1 where the name is transcribed as John Pikemere.

Slightly fuller for John Pikemere at http://histfam.familysearch.org/getperson.php?personID=I63918&tree=Welsh where it appears John and Joan had a daughter, Letis, born abt. 1430

The well-timed submission of Gwilym ap Gruffudd (d. 1431), landholder, during the Glyn D r revolt enabled him to add substantially to his lands at the expense of some of his kinsmen and to become the most powerful figure in the principality of north Wales, where his family, the Griffiths of Penrhyn, were to dominate until 1540. Married, secondly, Joan Stanley, daughter of Sir William Stanley of Hooton (Welsh Biography Online)

Biographical source include;

John Pykmere of Caernarvon is recorded in 1421 in the Act of Privy Council (Proceedings and ordinances of the Privy council of England Vol. 2 p. 303-4) and in 1440 in the patent rolls, again in connection with Caernarfon. (CPR p. 478)