The Chronicle of Adam of Usk

From Owain Glyndwr to the king of Scotland
Most high and mighty and redoubted lord and cousin, I commend me to your most high and royal majesty, humbly as beseemth me, with all honour and reverence. Most redoubted lord and right sovereign cousin, please it you and your most high majesty to know that Brutus, your most noble ancestor and mine, was the first crowned king who dwelt in this realm of England, which of old times was called Great Britain. The which Brutus begat three sons, to wit Albanact, Locrine and Camber. From which same Albanact you are descended in direct line. And the issue of the same Camber reigned royally down to Cadwalladar, who was the last crowned king of my people, and from whom I, your simple cousin, am descended in direct line; and after whose decease I and my ancestors and all my said people have been, and still are, under the tyranny and bondage of mine and your mortal foes the Saxons; whereof you, most redoubted lord and right sovereign cousin, have good knowledge. And from this tyranny and bondage the prophecy saith that I shall be delivered by the aid and succour of your royal majesty. But, most redoubted lord and sovereign cousin, I make grievous plaint to your royal majesty and right sovereign cousinship, that it faileth me much in men at arms. Wherefore, most redoubted lord and right sovereign cousin, I humbly beseech you, kneeling upon my knees, that it may please your royal majesty to send unto me a certain number of men at arms who may aid me and may withstand, with God's help, mine and your foes aforesaid; having regard, most redoubted lord and right sovereign cousin, to the chastisement of this mischief and of all the many past mischiefs which I and my said ancestors of Wales have suffered at the hands of mine and your mortal foes aforesaid. Being well assured, most redoubted lord and right sovereign cousin, that it shall be that, all the days of my life, I shall be bounden to do service and pleasure to your said royal majesty and to repay you. And in that I cannot send unto you all my businesses in writing, I despatch these present bearers fully informed in all things, to whom it may please you to give faith and credence in what they shall say unto you by word of mouth. From my court. Most redoubted lord and right sovereign cousin, may the Almighty Lord have you in his keeping.
From Owain Glyndwr to a lord in Ireland
Greetings and fullness of love, most dread lord and right trusty cousin. Be it known unto you that a great discord or war has arisen between us and our and your deadly foes, the Saxons: which war we have manfully waged now for nearly two years past, and which too, we purport and hope henceforth to wage and to bring to a good and effectual end, by the grace of God our Saviour, and by your help and countenance. But, seeing that it is commonly reported by the prophecy that, before we can have the upper hand in this behalf, you and yours, our well-beloved cousins in Ireland, must stretch forth hereto a helping hand; therefore, most dread lord and right trusty cousin, with heart and soul we pray you that your horsemen and footmen, for the succour of us and our people who now this long while we are oppressed by our said foes and yours, as well as to oppose the treacherous and deceitful will of those same our foes, you do despatch unto us as many as you shall conveniently and honourably be able, saving in all things your honourable estate, as quickly as may seem good to you, bearing in mind our sore need. Delay not to do this, by the love we bear you and as we put our trust in you, although we may be unknown to your dread person, seeing that, most dread lord and cousin, so long as we shall be able to wage manfully this war in our borders, as doubtless is clear unto you, you and all the other chieftains of your parts of Ireland will be in the mean time have welcome peace and calm repose. And because, my lord cousin, the bearers of these presents shall make things known unto you more fully by word of mouth, may it please you to give credence unto them in all things which they shall say unto you on our behalf, and as it may be your will, to confide in full trust, unto them whatsoever, dread lord and cousin, we your poor cousin may do. Dread lord and cousin, may the almighty preserve your reverence and lordship in long life and good fortune. written in North Wales, on the twenty-ninth day of November

Adam quotes these letters and reports that the bearers were taken in Ireland and beheaded. Adam often speaks sympathetically about the plight of his countrymen and the very many harsh things to be put in force against them that he heard proposed in parliament but he never openly supports with Owain. But later in the rebellion he took refuge with Owain while in disgrace with king Henry. Adam gives these letters as from 1401 when England was fighting on four fronts: a force under the king's second son crossed to Ireland to subdue a rebellion; the earl of Rutland had been despatched to repulse a French invasion of Gascony; the Scots were at war with England; and Owain. The tone of the letters seems to fit this date but Owain is exaggerating when he claims to have been in rebellion for nearly two years past — in November 1401 he had barely been in arms a year.
Some years before the first of these letters Owain had, of course, served with an English army against the Scots and the bards had sung of his exploits.
Llanerch Publishers have reprinted The Chronicle of Adam of Usk in paperback.