Having fought in the Second Boer War with the Imperial Yeomanry, Howard became Consul General for Crete in 1903, and three years later was sent to Washington as a counsellor at the embassy there. Esme Howard was married to Isabella Giovanna Teresa Gioachina Giustiniani-Bandini of Venice. In 1906, the Liberals won the general election and Howard's old friend whom he had known since 1894, Sir Edward Grey became Foreign Secretary, which greatly benefited his career. In 1908, he was appointed in the same role to Vienna, and that same year became Consul General at Budapest. Three years later, Howard was made Envoy Extraordinary and Minister Plenipotentiary to the Swiss Confederation, and in 1913 he was transferred to Stockholm, where he spent the whole of the First World War. During World War I, Sweden leaned in a pro-German neutrality and Howard's time as the British minister in Stockholm was a difficult one with the Swedish leaders openly expressing their hopes for a German victory. In an attempt to counter-act the pro-German sympathies of the Swedish elite, Howard sought to broaden his social contacts in Sweden, meeting with journalists, union leaders, businessmen, academics, clergymen, soldiers, and any local anglophiles in order to explain to them the British viewpoint. In 1916, having already been appointed CMG and CVO ten years earlier, he was knighted as KCMG, becoming KCB three years later.