Somme (river) invasion fleet of William the Conqueror assembled in the Bay of the Somme, at Saint-Valery-sur-Somme. The river also featured in the 1346 withdrawal of Edward III of England's army, which forded the river at the Battle of Blanchetaque during the campaign, which culminated in the Battle of Crécy. Crossing the river also featured prominently in the campaign which led to the Battle of Agincourt in 1415. In 1636, a Spanish army led by Thomas Francis, prince of Carignan, crossed the Somme defeating a French army during the Thirty Years War threatening Paris. Most famously, the Battle of the Somme, during
Battle of Agincourt no need of their help". The field of battle was arguably the most significant factor in deciding the outcome. The recently ploughed land hemmed in by dense woodland favoured the English, both because of its narrowness, and because of the thick mud through which the French knights had to walk. Accounts of the battle describe the French engaging the English men-at-arms before being rushed from the sides by the longbowmen as the mêlée developed. The English account in the "Gesta Henrici" says: "For when some of them, killed when battle was first joined, fall at the front, so great was