Itzamnaaj Bʻalam II, known to modern writers as Shield Jaguar II, becomes in 681 the ruler of Yaxchilan, a prosperous Maya site on an omega-shaped loop in the Usumacinta River in present-day Chiapas, Mexico.

Born in 647 to Lady Pacal and Yaxun B'alam III, is grandmother was Lady Xibalba, a noblewoman.

Little is known of Itzamnaaj Bʻalam's early life except that when he was eleven years old one of his siblings participated in a war that involved Pacal, the famous king of Palenque.

In order to become king, Itzamnaaj Bʻalam defeats Ah Ahaual (a Mayan noble) in war and takes him captive to Yaxchilan.

At the age of thirty-four, around October 23, 681, he becomes king of Yaxchilan.

He is married to his aunt, Lady Xoc, who holds a great amount of power.