Terrence O'Conner, the son of an officer in the "Mayo Fusiliers," joins the regiment as an ensign when it is called out to Portugal to fight the French in the Peninsular War. Terrence quickly distinguishes himself in early battles and is with Sir John Moore when that general invaded Spain. General Moore was forced to retreat to the town of Corunna where the British beat the French and then retreated on their ships without Terrence. Terrence eventually leads a band of Portuguese irregulars and creates the Minho Regiment. He rescues his cousin from a convent and is present at the fall of Oporto.