He then turned to reorganise the system of justice, making the judges the direct ministers of the sovereign, personally responsible to him, and subject in certain cases to his final appeal. His biographer tells us that he keenly revised unjust judgments, and tradition exaggerated this into a preposterous legend. He caused a collection of the old laws to be compiled—carefully resisting any general new legislation, or the fusion of the Wessex, Mercian, and Kentish customs into a symmetrical code. His laws were a compilation, with selection of what was approved best, and rejection of what was condemned as obsolete or mischievous. In the spirit of conservative amendment which marks his whole career, he is careful to tell us that he “durst not venture to set down much of his own.” He was content with partial revision and excision, under the advice of his Witan. The combination in a code of Saxon, Anglian, and Kentish “dooms” gave a certain stimulus towards national union in a larger aggregate. But a much more powerful cause unexpectedly emerged out of the Danish invasions. By these savage shocks the royal houses that had ruled in Mercia, in East Anglia, in Northumbria, were not only overthrown, but were extinct. Alfred remained the one victorious king of the race of Cerdic, the legitimate sovereign of Wessex and Kent, the natural source of kingly authority wherever Danes were not in possession of rule. Having won back the western half of Mercia by the Peace of Wedmore, Alfred became its king by silent consent of its Anglian people. He did not fuse West Mercia with Wessex; he was not formally installed or crowned. He made Ethelred, the husband of his daughter Ethelfleda, alderman, and himself exercised the functions of king, with a separate Mercian administration and Witan. By this wise and tentative system of dual monarchy, Alfred was firmly seated the undisputed sovereign of Southern England from the mouth of the Thames to the Exe, ruling by his son-in-law all Central England west of Watling Street from the Severn to the Ribble. He thus became, but a few years after his romantic sortie from Athelney, the most powerful ruler holding the widest single realm within our island. This effected a practical supremacy over the main part of England proper, except for the Danes in the east. And he thus made it possible that there should be a true English kingdom, of which his son Edward, and his grandson Athelstan, were formally recognised as sovereigns.