He was his father's fifth son and the first of his father's second marriage. In 1735 he became King of Naples and Sicily and, in 1738, married Princess Maria Amelia of Saxony, by whom he fathered twelve children. In August 1759 his elder half-brother, King Ferdinand VI, died and Carlos III became King of Spain, leaving Naples and Sicily to his third son, Ferdinand. 
Carlos III has been described as "the perfect type of a benevolent despot". He had done much to improve the welfare of his Italian subjects and, when he returned to Spain, intended to do the same. There he separated church and state and, in 1767, expelled the Jesuits. His siding with France involved Spain in the Seven Years' War and this, in 1763, forced him to secede Florida to Britain. 
Lean and ascetic in appearance, Carlos III possessed the prominent Bourbon nose. Unlike his father and brother before him, he never allowed his wife to take control of him. Yet when his wife died one year after their return to Spain, he remained a widower. 
A great patron of the arts, he built the Prado gallery. His main passion was hunting and it was said that he wore his hunting clothes underneath his court dress so that he could hurry away as soon as court ceremonies were over. 
His eldest son, Filippo, was an imbecile and was consequently excluded from the succession in both Naples and Spain. Kept in close confinement in Naples, Filippo died eleven years before his father, who died in Madrid on 14 December 1788.
 

Source: Leo van de Pas