Joffrey Baratheon inherited and ruled the Seven Kingdoms after his father, King Robert Baratheon died. His mother is Queen Cersei Lannister and Joffrey is her oldest son. His personality is cruel, sadistic and rash.
Initially, Joffrey was betrothed to Sansa Stark. However, after the Stark family fell out of grace with the throne, Joffrey was engaged to Margaery of House Tyrell instead. It is at their wedding that Joffrey suddenly mysteriously chokes and dies, apparently poisoned by an unknown hand.
Joffrey was widely accused of being a product of incest between Cersei and her brother, Jaime Lannister.
In the show, Joffrey is acted by Jack Gleeson and is a main character in Season 1, 2, 3 and 4.