Maria Carolina of Austria, and later becoming Maria Carolina, Queen of Naples and the Two Sicilies was queen consort and "de facto" ruler of Naples from 1768 to 1799 and from 1799 to 1806, and of Sicily from 1768 until her death in 1814, though she had lost the "de facto" power in 1812. She was born an Austrian Archduchess and was a sister of Marie Antoinette. Wikipedia
The definitive Wikipedia entry for Marie Caroline Of Austria. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Marie_Caroline_of_Austria