Lord Orys II Baratheon, also known as The Lustful Stag, was the ruler of the Seven Kingdoms of Westeros and father to Renly Baratheon. He perished at the start of the second Greyjoy Rebellion from a mysterious fall into a bay.
Orys was a man of well noted over-indulgence. He often traveled across the Realm, speaking and feasting with his Lords, but he ignored the Iron Islands due to his dislike of the ironborn. Supposedly he fathered a bastard at almost every castle he visited and acknowledged each of them, creating the Children of the Stag - a group of diplomats that lived in Kings Landing for their home Lords.
Despite aboloshing taxes at the start of his reign, towards the end, he was known to have levied harder ones on his subjects. He contracted burgher taxmen to raise the taxes on his behalf. They were allowed to take equivilent goods to the value and many became rich and corrupt.
His ignorance of the Iron Isles though left the prickly Greyjoy lord feeling insulted, and his ensuing hatred seethed under the surface for years, eventually boiling over into the second Greyjoy Rebellion when King Orys refused an invitation to Pyke by saying: "Not even to make the eight."
Orys never lived to see the consequences of his actions. Before even the first battle of the rebellion the King died from a mysterious fall into a bay, the cause of which is still unknown.
"He's killing himself slowly. The drinking, the whoring. He'll catch a pox one of these days, and the realm will be better for it." - Renly Baratheon