22 July 1405:   Breton-French expedition sails from Brest to support Owain Glyn Dwr.

The year 1404 had been a quiet time for Owain Glyn Dwr. Despite the disappointment of the battle of Shrewsbury the summer before and the failure of an alliance with English rebels under “Hotspur Percy,” he had expanded his rule to cover nearly all of Wales. With the English for the moment fought to a standstill, Owain had used the breathing spell to consolidate his rule and to reach out to cement an alliance with the French.

Looking upon Wales as a potential “second front” in a renewed Hundred Years’ War with England, an active war party in the French court responded enthusiastically to Owain’s envoys, and committed themselves to landing a French expeditionary force in Wales the following summer.

1405 then, would be the year that the French alliance would be made to pay off for Owain. With their assistance he could at last finish the rebellion that he had begun over four years before, firmly establish his rule in Wales, and negotiate with the English from a position of strength.

The year, though, began badly. In February, a plot to abduct the twelve-year-old Earl of March to have him serve as the figurehead for a Welsh-inspired uprising against King Henry was foiled. In March a Welsh advance against Grosmont Castle in South Wales was surprised and defeated by an English force. At the beginning of May, a Welsh attack against Usk Castle was again surprised by a superior English force, this time under the personal command of the young Prince Harry. The eldest son of King Henry, Harry was beginning to build his reputation as a talented (and ruthless) field commander. The broken Welsh forces were pursued, cornered and massacred at Pwll Melyn (Yellow Pool) mountain. Only the outbreak of a Welsh-instigated uprising in the north of England prevented a full-scale invasion of South Wales by the English.

The Yorkshire rebellion was crushed at the battle of Shipton Moor at the end of May, but by then the long-awaited Breton-French expedition was beginning to assemble. Landing at Milford Haven at the beginning of August, the expedition was a potential juggernaut, boasting some 800 knightly men-at-arms, 600 crossbow men, and some 1200 infantry. Welshmen now flocked to Owain’s banner, and the combined Welsh-Breton-French army swept through South Wales, rolling back the English reconquest and pushing on to Cardiff, where they paused before launching a full-scale invasion of England, with Worcester as Owain’s first objective.

The surprise eruption of the Welsh into England caught King Henry with his pants down. Still mopping up in Yorkshire, Henry at first could do nothing more than send an urgent command to the five “Cinque Ports” of southern England to assemble themselves an improvised flotilla and sail off to attack the French fleet moored in Milford Haven. Here the hastily-armed English merchantmen scored a success, burning part of the French fleet and driving other ships away.

Meanwhile, Owain and Henry were locked in a race to Worcester. Owain won, and Worcester was sacked and burned by the jubilant Welsh before the army moved off to a nearby Celtic fort atop Woodbury Hill to await the arrival of the English. Arriving to find Worcester in ruins and themselves burned out of a snug billet, the English set up camp on Aberly Hill in view of the Welsh.

With two nearly matched forces confronting each other, the war lost its momentum as the two commanders tried to decide what to do next. The armies remained encamped for eight days, the time being spent in the best Medieval fashion with a series of individual knightly combats in the valley between the two hill camps.

However colorful and inspiring, gallant displays of chivalry would not decide the campaign. Deciding against a frontal attack on Owain’s army, Henry instead opted for a war of maneuver. He slipped his forces past the encamped allies, and moved into what remained of Worcester, establishing himself in a strong position behind Worcester’s still-intact fortifications.

Finding the English now in a position to block access to his supply base, news came to Owain of the English attack on Milford Haven, and with his troops in a near-panic, he could do little more than join in a headlong retreat back into South Wales.

Another promising Summer had again fizzled out for Owain without producing the decisive stroke he had been hoping for. But as most of his Breton and French allies set back for home on whatever transport they could commandeer, Owain could still count on considerable resources. It was too late in the year for Henry to mount an invasion of South Wales, and in the meantime Owain could count on a substantial war chest of French gold as well as the services of some 800 Breton and French infantrymen who had found themselves prioritized out of a ride home. While Henry returned to London to deal with his unending political difficulties, Owain could safely settle down for the winter, and ponder what opportunities the year 1406 would bring.

The stories featured 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 2006 Celtic Calendar, now available from the Celtic League American Branch.