The work of internal colonization he carried on with especial zeal. Most notable of all was his _retablissement_ of East Prussia, to which he devoted six million thalers (c. L900,000). His policy in respect of the towns was motived largely by fiscal considerations, but at the same time he tried also to improve their municipal administration; for example, in the matter of buildings, of the letting of domain lands and of the collection of the excise in towns. Frederick William had many opponents among the nobles because he pressed on the abolition of the old feudal rights, introduced in East Prussia and Lithuania a general land tax (the _Generalhufenschoss_), and finally in 1739 attacked in a special edict the _Legen_, i.e. the expropriation of the peasant proprietors. He did nothing for the higher learning, and even banished the philosopher Christian Wolff at forty-eight hours' notice "on pain of the halter," for teaching, as he believed, fatalist doctrines. Afterwards he modified his judgment in favour of Wolff, and even, in 1739, recommended the study of his works. He established many village schools, which he often visited in person; and after the year 1717 (October 23) all Prussian parents were obliged to send their children to school (_Schulzwang_). He was the especial friend of the _Franckische Stiftungen_ at Halle on the Saale. Under him the people flourished; and although it stood in awe of his vehement spirit it respected him for his firmness, his honesty of purpose and his love of justice. He was devoted also to his army, the number of which he raised from 38,000 to 83,500, so that under him Prussia became the third military power in the world, coming next after Russia and France. There was not a more thoroughly drilled or better appointed force. The Potsdam guard, made up of giants collected from all parts of Europe, sometimes kidnapped, was a sort of toy with which he amused himself. The reviewing of his troops was his chief pleasure. But he was also fond of meeting his friends in the evening in what he called his Tobacco-College, where amid clouds of tobacco smoke he not only discussed affairs of state but heard the newest "guard-room jokes." He died on the 31st of May 1740, leaving behind him his widow, Sophia Dorothea of Hanover, whom he had married on the 26th of November 1706. His son was Frederick the Great, who was the opposite of Frederick William. This opposition became so strong in 1730 that the crown prince fled from the court, and was later arrested and brought before a court-martial. A reconciliation was brought about, at first gradually. In later years the relations between father and son came to be of the best (see FREDERICK II., king of Prussia).