The beginning of Frederick III's reign was plagued by intermittent wars with Naples. In 1372 he was able to come to peace terms with Naples and the Papacy and was titled as a Tributary King of "Trinacria."
"Frederick the Simple" is often confused with an earlier Sicilian monarch, Frederick II, who chose to call himself "Frederick III" because he was the third son of another Sicilian king, Peter, even though he was actually only the second King Frederick to occupy the Sicilian throne.
See also: Monarchs of Naples and Sicily