Saudi king tightens grip with promotion of another son

Saudi King Salman on Sunday promoted one of his sons to the pivotal role of energy minister, strengthening his family's grip on the levers of power from oil to finance and defence.The appointment of Prince Abdulaziz bin Salman as the new energy minister mirrors the ascent of his half-brother Crown Prince Mohammed bin Salman, the de facto ruler.Prince Khalid bin Salman, their younger brother, is effectively in charge of the defence ministry.