Southern Italy covers the historical and cultural region that was once politically under the administration of the former Kingdoms of Naples and Sicily (officially denominated "Regnum Siciliae citra Pharum" and "ultra Pharum", that is "Kingdom of Sicily on the other side of the Strait" and "across the Strait"), and which later shared a common organization into Italy's largest pre-unitarian state, the Bourbon-led Kingdom of the two Sicilies. The island of Sardinia, which had never been part of the aforementioned region and had once been under the rule of the Alpine House of Savoy, is nonetheless often subsumed into the "Mezzogiorno".