The reigns of Edgar (1097-1107) and Alexander I (1107-1124) have been overshadowed by those of their father Mael Coluim III (1057-1093) and their younger brother David I (1124-1153). This joint biographical study of the two kings highlights that the kingship of the Scots was a family enterprise in the eleventh and twelfth centuries. The relatively peaceful succession of the three brothers, Edgar, Alexander I and David I, stands in sharp contrast with the violent deaths, civil wars and usurpations that marked the turbulent succession to William the Conqueror in England and Normandy. The book argues that the sibling relationships between the brothers and with other members of their family, especially their sisters Queen Matilda of England and Mary, Countess of Boulogne, allow us to take a new look at the key developments that took place in the kingdom of Scots at the beginning of the twelfth century. One twelfth-century historian, the monk Orderic Vitalis, wrote: 'all these brothers in turn reigned Scotland, giving abundant evidence of their good character and love of God; and they led praiseworthy lives in the way appropriate for young laymen.' This book tests the truth of Orderic's assessment.