Harlequin - Bernard Cornwell

It was the time when the English came across the Channel to take the battle of the French. The army was led by the King, the great lords and knights, but it is the archers, the common men, who are to be England's secret weapon.

Thomas of Hookton is one of those archers. But he is also on a personal mission - one he frequently forgets in the joy of fighting - to avenge his father's killing by a French raider and to retrieve his family's treasure. But the journey is far more complex and treacherous than he had expected and the enemy who awaits him could harness the power of Christendoom's greatest relic, the Grail itself.

The first book in the Grail Quest series ends in the greatest battle of Crécy, the beginning of what became known as the hundred Years' War.