The war against Napoleon began in 1794 and was to drag on for another 20 years. Porteus' tenure as Bishop of London saw not only services of thanksgiving for British victories at the Battles of Cape St. Vincent, the Nile and Copenhagen, but the great national outpouring of sorrow at the death of Nelson in 1805, and his state funeral service in St Paul's Cathedral in 1806. As Bishop of London, Porteus may have officiated at some of these services, although it is unlikely that he did so at Nelson's funeral, because of the Admiral's reputation as an adulterer.