Summer 1808 turning points: First Siege of Zaragoza, Battle of Bailén, and the British landing near Porto

Background. The Peninsular War escalated in 1808 after Napoleonic France occupied Spain. In June, Napoleon organized flying columns to pacify resistance. French forces besieged Zaragoza, while the Army of Andalusia prepared to confront Dupont's corps. British troops landed in Portugal in August to counter French occupation, marking a shift in the conflict's dynamics.

Siege of Zaragoza. French armies under Lefebvre-Desnouettes and Verdier besieged Zaragoza in summer 1808. Palafox's forces were defeated at Alagon and Épila, but the city resisted continuous artillery fire starting 30 June. French assaults failed, and Verdier withdrew on 14 August, recognizing the need to retreat after the French defeat at Bailén.

Battle of Bailén. The Battle of Bailén involved the Spanish Army of Andalusia under Castaños against Dupont's 2nd Gironde Observational Corps. Dupont's surrender on 19 July was considered the first open-field defeat of the Napoleonic army. This event caused French forces to retreat and led to court-martials for Dupont and his staff.

British Landing in Portugal. In August 1808, 15,000 British troops landed in Portugal under Lieutenant-General Arthur Wellesley. Wellesley defeated Delaborde at Roliça and Junot at Vimeiro. The landing near Porto was part of the broader British intervention against French occupation in the Iberian Peninsula.