In 1809 the Fifth Coalition was formed against France, though this was much smaller than previous coalitions, consisting of just Austria and the United Kingdom. That same year the 1st Battalion made its way to the Iberian Peninsula where it was to take part in the Peninsular War in Portugal and Spain. On 12 May, the 1st Battalion took part in the crossing of the River Douro, an operation that ended so successfully that the French Army were in full retreat to Amarante after the actions in Oporto and its surrounding areas.