King Abdullah's trusted brother named Second in Line to Throne. He is 21 years younger.

Saudi Arabia named Prince Muqrin bin Abdulaziz as second in line to the throne, the latest royal promotion as King Abdullah confronts unprecedented political instability in the Middle East and economic changes at home.
Muqrin, the king’s half-brother who was born in 1945, was made second crown prince alongside his duties as second deputy prime minister, the official Saudi Press Agency said yesterday, citing a royal decree. King Abdullah named his defense minister and half-brother Prince Salman bin Abdulaziz, born in 1935, crown prince in June 2012, making the traditionalist former governor of Riyadh next in line to become king.
“By many accounts, Prince Muqrin is a close and trusted adviser to King Abdullah,” said Fahad Nazer, a political analyst at Vienna, Virginia-based JTG, and a former official at the Saudi embassy inWashington. “His relative youth, extensive experience in government and knowledge of the West make him an attractive candidate. He appears to be a generally popular figure among many Saudis, whereas other royals may be more polarizing.”