After visiting Naples in 1850, Gladstone began to support Neapolitan opponents of the Bourbon rulers: his "support" consisted of a couple of letters that he sent from Naples to the Parliament in London, describing the "awful conditions" of the Kingdom of Southern Italy and claiming that "it is the negation of God erected to a system of government". Gladstone's letters provoked sensitive reactions in the whole of Europe and helped to cause its diplomatic isolation before the invasion and annexation of the Kingdom of the Two Sicilies by the Kingdom of Sardinia, with the following foundation of modern Italy. Administratively, Naples and Sicily remained separate units; in 1858 the Neapolitan Postal Service issued her first postage stamps; that of Sicily followed in 1859.