The Papal States was an Italian kingdom ruled by the
popes as temporal monarchs from
754 to
1870. In their capacity as rulers of the Papal States, medieval popes often rode at the head of armies, levied taxes, passed laws, and retained
feudal vassals, just like any other earthly king.
The Papal States originated when the Frankish king Pepin the Short donated Lombardy to the Papacy. Later gifts and conquests increased the papal domains, and at its height in the 1200s the Papal States encompassed almost all of Italy, from the Po River Valley in the north, to Naples in the south.
The Papal States lasted until 1870, when Italian king Victor Emmanuel II finally annexed Rome itself, the last vestige of the once vast papal domain, as part of the Italian Risorgimento. The popes refused to accept Italian sovreignty, however, and contested the loss of their lands until the Lateran Treaty of 1929, which granted the papacy Vatican City as an independent nation-state.