At the age of forty he succeeded his father whom he physically resembled, though a little shorter and stouter. He also had his father's placid temperament and passion for hunting. He married his first cousin, Maria Luisa of Parma, who was later on described as strongminded, ugly and toothless. She also took as her lover an impecunious young nobleman, Manuel Godoy. Godoy virtually ruled Spain for twenty years, living with the King and Queen in a strange m‚nage-a-trois. The Queen gave birth to twelve children of which the last four were rumoured to have been fathered by Godoy. 
To regularize his position at court, in 1797 Manuel Godoy married the king's first cousin. However, after producing only the one daughter, they separated in 1808. The king described his life to 
Napoleon as: "Every day, winter and summer, I went shooting till twelve, had dinner, and at once returned to shooting until the fall of the evening. Manuel told me how things were going; and I went to bed to begin again the same life the next day unless any important ceremony prevented me." 
The French Revolution induced Godoy to declare war on France, but France then took control of Spain. In 1808 a popular uprising overthrew Godoy and forced Carlos IV to abdicate in favour of his son, Ferdinand. However, two months later Napoleon summoned the new king, his parents and Godoy to Bayonne, where he forced the young king and his father to cede the crown to France. 

Carlos IV, Maria Luisa and Godoy first went to live at Compiegne; but in 1819, when peace had been restored in Europe, they moved to Rome. Carlos IV went for a visit to his brother in Naples and while there Maria Luisa died, tended to the last by Godoy. The heartbroken Carlos IV wrote a touching letter to Godoy and a month later died himself in Naples, aged sixty. Godoy survived until 1852 when he died in Paris.
 

Source: Leo van de Pas