Few sources remain which describe the rebellion of the rebellion of Owain Glyn Dwr that come from the Welsh side. The earliest of these sources is a Welsh chronicle, which narrates Welsh history to the year 1422. This manuscript, Peniarth MS 22, does contain some errors, such as dating the battle of of Pilleth to 1403 instead of 1402, but it is a valuable piece of evidence showing the progress of the Welsh rebellion between 1400 and 1415.
1400 – Henry went to Scotland and with him a great host. While he was unoccupied there, one of his lords told him he had better have faithful men in Wales, for he said that Owain ap Gruffydd would wage war against him. Therewith Lord Talbot and Lord Grey of Ruthin were sent to make sure of Owain and they understood the task. But the man escaped into the woods; the time was the feast of St.Matthew in autumn (September 21). The following summer Owain rose with 120 reckless men and robbers and he brought them in warlike fashion to the uplands of Ceredigion; and 1,500 men of the lowlands of Ceredigion and of Rhos and Penfro assembled there and came to the mountain with the intent to seize Owain. The encounter between them was on Hyddgant Mountain, and no sooner did the English troops turn their backs in flight than 200 of them were slain. Owain now won great fame, and a great number of youths and fighting men from every part of Wales rose and joined him, until he had a great host at his back.
1402 – Owain and his host went and attacked in the neighbourhood of Ruthin and Dryffryn Clwyd, and Reginald Grey, lord of that region, took the field against him. And lord Grey was there captured and long held a prisoner by Owain in wild and rocky places; at last he was ransomed for 11,000 marks.
1403 – Owain rose with a great host from Gwynedd, Powys, and the South, and made for Maelienydd; where the knights of Herefordshire gathered together against him. The battle between them was fought near Pilleth, and there Sir Robert Whitney and Sir Kinard de la Bere were slain and Sir Edmund Mortimer and Sir Thomas Clanvow were captured and most of the English host slain. In the following August Owain came to Glamorgan and all Glamorgan rose with him; Cardiff and Abergavenny were burnt.
1404 – Owain won the castles, namely Harlech and Aberystwyth. In the same year was the slaughter of the Welsh on Campstone Hill and another of the English at Craig y Dorth, between Penclawdd and Monmouth town. Here the more part of the English were slain and they were chased up to the town gate.
1405 – A slaughter of the Welsh on Pwll Melyn Mountain, near Usk, where Gruffydd ab Owain was taken prisoner. It was now the tide began to turn against Owain and his men. At this time Glamorgan made its submission to the English, except a few who went to Gwynedd to their master.
1406 – Gower and Ystrad Twyi and most Ceredigion yielded and took the English side.
1407 – The English prince came with a great host to lay siege to Aberystwyth castle, nor did he retire until he had received a promise of the surrender of the castle after a short interval, with four of the most puissant men in the castle as pledges of the bargain. Before the day Rhys the Black went to Gwynedd to ask Owain’s leave to surrender the castle to the English. Owain kept Rhys with him until he had gathered his power around him and then went with Rhys to Aberystwyth, where he threatened to cut off Rhy’s head, unless he might have the castle; whereupon the castle was given to Owain.
1408 – Now befell the second siege of the above castle and, without stirring from the spot, it was won; thence the host went to Harlech, where many gentlemen of Wales met their death; at last the castle was perforce given up to the English.
1409 – The men of Owain made an attack on the borders of Shropshire and ther Rhys the Black and Philip Sudamore were captured. The one was sent to London and the other to Shrewsburym to be drawn and quartered. Thenceforth Owain made no great attack until he disappeared.
1412 – Rhys ap Tudor of Anglesey and Ednyfed his brother were captured. They were executed in Chester.
1415 – Owain went into hiding on St. Matthew’s Day in Harvest (September 21), and thereafter his hiding place was unknown. Very many said that he died; the seers maintain he did not.
This section is republished from Owen Glendower – Owen Glyn Dwr, by John Edward Lloyd (Oxford, 1931).