 In 1879 Lascelles became Consul-General in Bulgaria, which had been an autonomous principality since the Treaty of Berlin of 1878.He remained in Bulgaria until 1887, and was then Minister (similar to ambassador) to Romania from 1887 to 1891 and to Persia from 1891 to 1894, where his niece Gertrude Bell visited him, starting a lifelong passion for travel.He served briefly as Ambassador to Russia between 1894 and 1895, but in the latter year he was appointed to succeed Sir Edward Malet as Ambassador to Germany.