As minister at Copenhagen, Paget saw the accession of Christian IX at the close of 1863, and had to play a leading part in regard to the Schleswig-Holstein difficulty in 1864; nor was his position much less difficult when in 1866 Prussia meditated war against Austria. On 9 June 1866, he was sent to Portugal as envoy extraordinary. Appointed on 6 July 1867 to Italy as envoy extraordinary and minister plenipotentiary to Victor Emmanuel, he represented Great Britain in Italy during one of the most critical periods of Italian history; he saw the entry of the Italian troops into Rome and the beginning of a new era of national life. It is admitted that in this trying period his tact was conspicuous. He remained in Italy for a long time, becoming ambassador extraordinary on 24 March 1876. On 12 September 1883 he relinquished this post and, after a short period of leave, became ambassador at Vienna on 1 January 1884. From that post he retired on 1 July 1893.