6 July 1403:   Carmarthen surrenders to Owain Glyn Dwr.

20 July 1403:   The Battle of Shrewsbury: English rebels under “Hotspur” Percy defeated by royal forces, forestalling alliance with the Welsh.

King Henry’s attempt to subdue the Welsh rebellion in the summer of 1402 had ended in disaster, with his army cut to pieces on the hillside of Bryn Glas, and one of his key noblemen, Sir Edmund Mortimer, gone over to the Welsh side. When Mortimer called for English nobles to join him and Owain Glyn Dwr in restoring the former king Richard II to the throne, the powerful Percy family began to consider joining the rebellion. For his part Owain may or may not have believed that the deposed Richard was still alive, as many said, but for whoever did succeed in overthrowing Henry, an independent Wales would be the price for Owain’s support. The Percy family, long restive under the rule of the usurper Henry Bolingbroke, would gain increased power and autonomy in their lands in northern England, and a free hand to pursue their private wars against the Scots.

As the campaigning season approached in the spring of 1403 it seemed that final victory was at last within Owain’s grasp. Not only were the Percys and several other nobles joining in revolt against Henry, but Breton privateers were joining in the conflict. With a wink and a nod from their still officially neutral Duke, ships set out from St. Malo and other ports to harass English shipping in the English Channel and interdict English attempts to resupply their remaining Welsh castles by sea.

If Owain’s forces could link up with Percy, the combined army could force a showdown with King Henry and win the rebellion in one summer afternoon. But before he could do so, Owain first had to secure his backfield in South Wales. In a lightning campaign he struck out against the isolated and understrength English garrisons there. On 2 July he took Dynevor castle, captured Llandovery the next day, and Llandeilo the day after. Finally, on 6 July he captured the key fortress of Carmarthen.

On the very day Owain received the surrender of Carmarthen, “Hotspur” Percy, unwilling to wait for his dad to join him with reinforcements, gathered what troops he had and set out from Chester town, moving southwards to link up with Owain and hopefully catching Henry between them. Owain, however, was stopped by a surprise attack by an army of Flemings who came boiling up out of the southwestern county of Pembrokeshire. These were descendants of European refugees who had been settled in southwest Wales as a garrison population by the Normans. Disinclined to speak Welsh or be ruled by a Welsh prince, their descendants live to this day in what is still known as “Little England beyond Wales” in Pembrokeshire.

Fighting with an edge of desperation, the Flemings’ improvised army proved surprisingly effective, and it took Owain until 12 July to break through them and resume his march on England. But by then the summer rains had begun, and the soggy Welsh weather that had so often bogged down his enemies now impeded Owain.

While Owain cursed the mud, Henry moved with dispatch to outrun him to the junction with Hotspur. On 20 July the forces of Henry and Hotspur collided in a pea field north of Shrewsbury. In an afternoon of bitter fighting, the outnumbered Hotspur nearly pulled off a victory, but when he was killed, his ramshackle army collapsed. According to legend, Owain’s advance guard, and perhaps Owain himself, emerged from the Welsh hills just in time to witness the final debacle.

Though a promising summer had ended in a colossal disappointment for Owain, the year’s events still left him in a strong position, in command of nearly all of Wales. The English, whose energies that year had gone mainly into killing one another, were worse off than before. By the time Henry mopped up the last of the English rebellion, it was too late in the season, and he was too broke, to do more than launch a strategically worthless terror raid into north Wales.

But for Owain, the most troublesome result of the Shrewsbury campaign was not yet apparent. The battle marked the coming of age of Henry’s son Henry, who having proven himself in battle at Shrewsbury now demanded an independent command and a more prominent role in strategic decision-making. The young prince Henry, who in time ascended the throne as Henry V, would prove to be one of England’s most capable, and utterly ruthless, commanders.

The stories in This Month in Celtic History are drawn from the over 1000 anniversaries of people and events from the histories of the six Celtic nations of Ireland, Scotland, Wales, Brittany, Cornwall, and the Isle of Mann in the 2004 Celtic Calendar, now available from the Celtic League American Branch.