of inviting German colonists to their vacant domains. More extensive immigrations followed, in the course of which the whole of Silesia was covered with German settlements. The numerous townships which then sprang up acquired rights of self-govern- ment according to German law, Breslau being refounded about 1 250 as a German town, and a feudal organization was introduced among the landholding nobility. By the end of the 13th century Silesia had virtually become a German land.
This ethnical transformation was accompanied by a great rise in material prosperity. Large areas of forest or swamp were reclaimed for agriculturs; the great Silesian industries of mining and weaving were called into existence, and Breslau grew to be a leading centre of exchange for the wares of East and West . The growing resources of the Silesian duchies are exempli- fied by the strength of the army with which Henry II., duke of Lower Silesia, broke the force of the Mongol invasion at the battle of Liegnitz (1241), and by the glamour at the court of the Minnesinger, Henry IV. (1 266-1 290) . This prosperity, however, was checked by a growing tendency among the Silesian dynasties to make partitions of their territories at each new succession. Thus by the end of the 14th century the country had been split up into 18 principalities: Breslau, Brieg, Glogau, Jauer, Liegnitz, Munsterberg, 01s, Schweidnitz and Steinau in Lower Silesia; Beuthen, Falkenberg, Kosel, Neisse, Oppeln, Ratibor, Strehlitz, Teschen and Troppau in the upper district. The petty rulers of these sections wasted their strength with internecine quarrels and proved quite incompetent to check the lawlessness of their feudal vassals. Save under the vigorous rule of some dukes of Lower Silesia, such as Henry I. and Bolko I., and the above- named Henry II. and IV., who succeeded in reuniting most of the principalities under their sway, the country fell into a state of growing anarchy.
Unable to institute an effective national government, and unwilling to attach themselves again to Poland, the Silesian princes began about 1290 to seek the protection of the German dynasty then ruling in Bohemia. The intervention of these kings resulted in the establishment of their suzerainty over the whole of Silesia and the appropriation cf several of its petty states as crown domains. The earliest of these Bohemian overlords, King John and the emperor Charles IV., fully justified their intrusion by the vigorous way in which they restored order and regularized the administration; in particular, the cities at this time attained a high degree of material prosperity and political importance. Under later rulers the connexion with Bohemia brought the Silesians no benefit, but involved them in the destructive Hussite wars. At the outbreak of this conflict in 1420 they gave ready support to their king Sigismund against the Bohemian rebels, whom they regarded as dangerous to their German nationality, but by this act they exposed themselves to a series of invasions (1425-1435) by which the country was severely devastated. In consequence of these raids the German element of population in Upper Silesia permanently lost ground ; and a complete restitution of the Slavonic nationality seemed imminent on the appointment of the Hussite, George Podiebrad, to the Bohemian kingship in 1457. Though most of the Silesian dynasts seemed ready to acquiesce, the burghers of Breslau fiercely repudiated the new suzerain, and before he could enforce his claims to homage he was ousted by the Hungarian king, Matthias Corvinus, who was readily recognized as overlord (1469). Matthias enforced his authority by the vigorous use of his mercenaries and by wholesale confiscations of the lands of turbu- lent nobles. By instituting a permanent diet of Silesian princes and estates to co-operate with his vicegerent, he took an important step towards the abolition of particularism and the establishment of an effective central government. In spite of these reforms the Silesians, who felt severely the financial exactions of Matthias, began to resent the control of the Bohemian crown. Profiting by the feebleness of Matthias' successor Vladislav, they extorted concessions which secured to them a practical autonomy. These privileges still remained to them at the outset of the religious Reformation, which the Silesians, in spite of their Catholic zeal during the Hussite wars, accepted readily and
carried out with singularly little opposition from within or without. But a drastic revolution in their government was imposed upon them by the German king, Ferdinand I., who had been prevented from interference during his early reign by his wars with the Turks, and who showed little disposition to check the Reformation in Silesia by forcible means, but subse- quently reasserted the control of the Bohemian crown by a series of important enactments. He abolished all privileges which were not secured by charter and imposed a more rigidly centralized scheme of government in which the activities of the provincial diet were restricted to some judicial and financial functions, and their freedom in matters of foreign policy was withdrawn altogether. Henceforth, too, annexations of territory were frequently carried out by the Bohemian crown on the extinction of Silesian dynasties, and the surviving princes showed an increasing reluctance to the exercise of their authority. Accordingly the Silesian estates never again chose to exercise initiative save on rare occasions, and from 1550 Silesia passed almost completely under foreign administration.
An uneventful period followed under the rule of the house of Habsburg, which united the kingship of Bohemia with the archduchy of Austria and the imperial crown. But this respite from trouble was ended by the outbreak of the Thirty Years' War (1618-48), which brought Silesia to the verge of ruin. Dis- quieted by some forcible attempts on Rudolph II. 's part to suppress Protestantism in certain parts of the country, and mistrusting a formal guarantee of religious liberty which was given to them in 1609, the Silesians joined hands with the Bohemian insurgents and renounced their allegiance to their Austrian ruler. Their defection, which was terminated by a capitulation in 1621, was not punished severely, but in spite of their attempt to maintain neutrality henceforth they were quite unable to secure peace. Silesia remained a principal objective of the various contending armies and was occupied almost continuously by a succession of ill-disciplined mercenary forces whose depredations and exactions, accentuated at times by religious fanaticism, reduced the country to a state of helpless misery. Three-quarters of the population are estimated to have lost their lives, and commerce and industry were brought to a standstill. Recovery from these disasters was retarded by the permanent diversion of trade to new centres like Leipzig and St Petersburg, and by a state of unsettlement due to the govern- ment's disregard of its guarantees to its Protestant subjects. A greater measure of religious liberty was secured for the Silesians by the representatives of King Charles XII. of Sweden on their behalf, and effective measures were taken by the emperor Charles VI. to stimulate commercial intercourse between Silesia and Austria. Nevertheless in the earlier part of the 18th century the condition of the country still remained unsatisfactory.
An important epoch in the history of Silesia is marked by the year 1 740, when the dominion of Austria was exchanged for that of Prussia. Availing himself of a testamentary union made in 1 537 between the duke of Liegnitz and the elector of Brandenburg, and of an attempt by the elector Frederick William to call it into force in spite of its annulment by Ferdinand I. in 1546, Frederick II. of Prussia raised a claim to the former duchies of Liegnitz, Brieg, Jagerndorf and Wohlau. The empress Maria Theresa, who was at this time involved with other enemies, was unable to prevent the occupation of Lower Silesia by Frederick and in 1 741 ceded that province to him. In the following year Frederick renewed his attack and extorted from Austria the whole of Silesia except the districts of Troppau, Teschen and Jagerndorf, the present province of Austrian Silesia.
Though constrained by the general dangers of her position to make terms with Prussia, Maria Theresa long cherished the hope of recovering a possession which she, unlike her predecessors, valued highly and held by a far better title than did her opponent. A second war which Fiederick began in 1744 in anticipation of a counter-attack from her only served to strengthen his hold upon his recent conquest; but in the famous Seven Years' War (q.v.) of 1756-63 the Austrian empress, aided by France and Russia, almost effected her purpose. Silesia was repeatedly overrun by