Philippe Barbour marks the the 600th anniversary of the battle of Agincourt by following in the footsteps of the English army.

Once more unto the breach, dear readers! After revisting Waterloo two hundred years after Napoleon’s defeat, I’ve travelled back even further in time, to six hundred summers ago when King Henry V reignited the Hundred Years War begun by his great-grandfather, Edward III.

Harry reasserted the English royals’ claim to the French throne to compensate for being the son of a usurper and to exploit cross-Channel civil war. But if Hal’s French foray ended in triumph, his foolhardy expedition lay on a knife-edge until the dénouement.

Let me lead you along Harry’s route, from Seine to Calais, via the Somme and of course Agincourt – except the place is in fact called Azincourt in French. There are many confusions to confront along the way, propagated by centuries of English propaganda, by Shakespeare, in his rousing Henry V, and by the way that play was exploited. Despite Laurence Olivier’s wartime film version of the Bard’s drama, in reality Henry V’s English army arrived as a feared, detested invading force… a little like the Germans racing into France in 1940.

Following the course of Hal’s army from Harfleur to Azincourt offers a fascinating way to discover Normandy’s dramatic eastern coast.

Less known than the sandy D-Day beaches of Western Normandy, its staggering cliffs mirror those of southern England.

Knowing Hal’s fleet was coming their way, the French military lay in wait at Honfleur, nowadays a gorgeous tourist trap at the southern mouth of the Seine. But the English made for Harfleur, then the major harbour on the Seine estuary’s north side. In mid-August, Henry’s troops set foot on the outsized pebbles near Le Havre.

Harfleur, surprised by the English armada, was meant to fall immediately. It withstood for a month before its walls were so famously breached. The town was destroyed, but the English army was decimated by dysentry. Today, Harfleur’s later medieval remnants look meagre, swamped by Le Havre’s suburbs. Most English visitors may not consider lingering in Le Havre. I’m fascinated by the place, with its breezy post-war boulevards, masterminded by concrete-building pioneer, Auguste Perret; its massive marina; trendy new public baths, designed by Jean Nouvel… and the fabulous waterside Musée Malraux, displaying sublime marine canvases by the likes of Monet, Boudin and Dufy. It still came as a surprise to me, though, when UNESCO declared Le Havre a World Heritage Site.

Sticking close to the coast as they marched eastwards, Henry’s troops had no time to contemplate Normandy’s most sensational rock formations, at Etretat, but surely medieval soldiers would have been awed by the way nature appears to have carved great castle gates and rocketing pinnacles out of the cliffs. Henry’s army avoided the string of major harbours enroute, but Fécamp and Dieppe were familiar names, because of cross-Channel raids and major pilgrimage churches, the latter still standing. These ports are fun places to visit now, with their gritty mix of fishing, tourism, and seafood restaurants. Also hunt out exquisite, more secluded spots like Les Petites Dalles and Veules-les-Roses. Hal steered clear of Dieppe, but made the garrison in the awesome hilltop fort of Arques-la-Bataille just inland submit. Today, the vast ruins are too dangerous to penetrate.

At the jaded town of Eu, you reach the historic frontier between Normandy and Picardy. In the crypt of Eu’s massive medieval church, I encountered a tomb effigy strewn with lilies, symbolic of French royalty – the figure was Charles d’Artois, one of the most significant French nobles to be captured at Azincourt.

The next crucial obstacle for the English army was the huge mouth of the Somme. St-Valéry still offers a stunning viewpoint over the estuary. Henry’s troops were being shadowed by the French. Heading far inland, the English gave them the slip at Béthancourt, dashing over the Somme. When I visited this tranquil spot, a mother duck was crossing anxiously with her ducklings.

The English army was focused on its march to Calais, but news of its approach terrorised locals. Many villages in these parts had developed ways to hide from marauding militias. None was cleverer than Naours, where villagers dug out a sophisticated underground village. Visit this amazing parallel world and learn how it went on to serve different sides in First and Second World Wars.

Moving to St Crispin’s Day, 25 October 1415. The English and French armies finally prepared for battle around Azincourt. Today, it’s a sweet, sleepy village, twee-looking at first sight because of the life-size cartoon cut-outs of medieval soldiers along the roadsides. The central barn-like museum on the massively important battle is, however, excellent. It’s impressive to see such a measured presentation of such a major defeat.

The trail to the battlefield itself lacks excitement but it’s true the English victory here in 1415 was staggering. While vast swathes of the French aristocracy were killed, few perished on the English side. The English archers’ devastating longbows helped win the day, along with the weather… heavy rain bogged down the French in their heavy armours. There’s an irony, though, to the Shakespearean speech in praise of the ‘band of brothers’ who beat the French on St Crispin’s Day. Twins St Crispin and Crispinian were, according to legend, peace-seeking Christian missionaries of the 3rd century, martyred in the Picardy city of Soissons by Romans.

After Hal’s great victory, the English and French crowns were briefly united. God was seen to be on the English side. But divine favour, or good fortune, technological advantage and superior strategy, can change sides rapidly. Before too long Joan of Arc would ride in to help boot the English out of France. Those bitter-sweet historic commemorations will have to wait until 2030...