Shards of a Broken Crown. Raymond E. Feist

The fourth book in the bestselling Serpentwar series.The demon is no more . . .The enemy has been routed, yet peace still eludes the Kingdom. Midkemia lies in smouldering ruins following the Demon King’s siege.And a new threat is arising from the ashes of war: the fearsome Fadawah, former Commanding General of the Army of the Emerald Queen. He has grasped the fallen reins of command and seeks to forge a personal empire out of the wreckage of the Western Realm.And so it falls to two young men – Jimmy and Dash – grandsons of the late Duke James, to gather the shards of the broken crown and resurrect the Kingdom to its former glory.