The Walcheren Campaign was an unsuccessful British expedition to the Netherlands in 1809 intended to open another front in the Austrian Empire's struggle with France during the War of the Fifth Coalition. Around 40,000 soldiers, 15,000 horses together with field artillery and two siege trains crossed the North Sea and landed at Walcheren on 30 July. This was the largest British expedition of that year, larger than the army serving in the Peninsular War in Portugal. The Walcheren Campaign involved little fighting, but heavy losses from the sickness popularly dubbed "Walcheren Fever". Over 4,000 British troops died (only 106 in combat) and the rest withdrew on 9 December 1809.