Francis was born the son of Ferdinand I of the Two Sicilies and his wife Archduchess Maria Carolina of Austria in Naples.

In 1796 Francis married his double first cousin Archduchess Maria Clementina of Austria, daughter of Leopold II, Holy Roman Emperor.

When she died in 1801, he married his paternal first cousin María Isabella, youngest daughter of King Charles IV of Spain.

[2] On the abdication of Napoleon I, his father returned to Naples and suppressed the Sicilian constitution, incorporating his two kingdoms into that of the Two Sicilies (1816); Francis then assumed the revived title of duke of Calabria.

[4] He took little part in the government, which he left in the hands of favourites and police officials, and lived with his mistresses, surrounded by soldiers, ever in dread of assassination.