Alexander (Alaxandair mac Maíl Coluim) was the 4th son of Malcolm III. He succeeded to the throne on the death of his brother Edgar, and married Sybilla and illegitimate daughter of Henry I of England who had married Alexander?s sister Edith (Matilda). Sybilla was not well received by the Scots and said to ?lack both beauty and modesty?.
Alexander helped Henry I in his campaigns in Wales, and earned the name ?The Fierce? for the way in which he put down an uprising in Moray. He sought to continue the work of his mother Margaret and introduced English style reforms into the Church and reform of civil government introducing the offices of chancellor and sheriffs. The earliest known Scottish coins dated from his reign. He appointed his mother?s biographer Turgot as see to St Andrews which was influential in her eventual canonisation.
He died without legitimate children and was succeeded by his brother David I (britroyals.com)