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 the Kalka River son-in-law, Prince Mstislav the Bold of Galich, whom he convinced to help fight the Mongols. Mstislav the Bold formed an alliance of the Rus' princes including Mstislav III of Kiev. The combined Rus' army defeated the Mongol rearguard at first. The Rus' pursued the Mongols, who were in a feigned retreat, for several days, which spread out their armies. The Mongols stopped and assumed battle formation on the banks of the Kalka River. Mstislav the Bold and his Cuman allies attacked the Mongols without waiting for the rest of the Rus' army and were defeated. In the ensuing confusion, several