FERDINAND I. Roman emperor, was born at Alcala de Henares on March Io, 15o3, his father being Philip the Handsome, son of the emperor Maximilian I., and his mother Joanna, princess of Castile and Aragon. In April 1521 the emperor granted to him the archduchies and duchies of upper and lower Austria, Carinthia, Styria and Carniola, adding soon afterwards the county of Tirol and the hereditary possessions of the Habs burgs in south-western Germany. About the same time Ferdi nand was appointed to govern the duchy of Wurttemberg, which had come into the possession of Charles V. ; and in May 1521 he was married at Linz to Anna (d. 1547), a daughter of Ladislaus, king of Hungary and Bohemia. In 1521 also he was made president of the council of regency (Reichs-regiment), appointed to govern Germany during the emperor's absences, and the next five years were occupied with imperial business, in which he acted as his brother's representative, and in the government of the Austrian lands.
In Austria and the neighbouring duchies Ferdinand sought at first to suppress the reformers and their teaching, a policy which increased his difficulties in quelling risings in the districts under his rule after the Peasant's War broke out in 1524. In August 1526 his childless brother-in-law, Louis II., king of Hungary and Bohemia, was killed at the battle of Mohacs, and the archduke at once claimed both kingdoms, both by treaty and by right of his wife. He was chosen king of Bohemia in October 1526, and crowned at Prague in the following February. But in Hun gary John Zapolya, supported by the national party and soon afterwards by the Turks, offered a sturdy resistance. Although Ferdinand was chosen king at Pressburg in December 1526, and after defeating Zapolya at Tokay was crowned at Stuhlweissen burg in November 1527, he was unable to take possession of the kingdom. The Bavarian Wittelsbachs, incensed at not securing the Bohemian throne, were secretly intriguing with his foes ; the French, after assisting spasmodically, made a formal alliance with Turkey in 1535; and Zapolya was a very useful centre for the enemies of the Habsburgs. A truce made in 1533 was soon broken, and the war dragged on until 1538, when by the treaty of Gross wardein, Hungary was divided between the claimants. The kingly title was given to Zapolya, but Ferdinand was to succeed. Mean while, in January 1531, he had been chosen king of the Romans, or German king, at Cologne. He had earned this honour by his loyalty to his brother, Charles V., whom he had represented at several diets. In religious matters the king was now inclined to steer a middle course, and in 1532 he agreed to the religious peace of Nuremberg, receiving in return from the Protestants some assist ance for the war against the Turks. In 1534, however, Philip, landgrave of Hesse, and his associates had succeeded in conquer ing Wurttemberg on behalf of its exiled duke, Ulrich (q.v.), and neither Charles nor Ferdinand could send much help to their lieutenants. They were consequently obliged to consent to the treaty of Cadan, made in June 1534, by which the German king recognized Ulrich as duke of Wurttemberg though under Austrian suzerainty.
In Hungary the peace of 1538 was not permanent. When Zapolya died in July 154o a powerful faction refused to admit Ferdinand's right of succession, and put forward Zapolya's young son John Sigismund as a candidate. The cause of John Sigismund was espoused by the Turks and by Ferdinanci's other enemies. The king repeatedly sought to make peace with the sultan, but his envoys were haughtily repulsed. In 1544, however, a short truce was made. This was followed by others, and in 1547 one was concluded for five years, but only on condition that Ferdinand paid tribute for the small part of Hungary which remained in his hands. The struggle was renewed in 1551 and was continued in the same desultory fashion until 1562, when a truce was made which lasted during the remainder of Ferdinand's lifetime. During the war of the league of Schmalkalden in 1546 and 1S47 the king had taken the field primarily to protect Bohemia, and after the con clusion of the war he put down a rising in this country with some rigour. About 1546 he began to take up a more independent posi tion in imperial politics. Although Charles had crushed the league of Schmalkalden he had refused to restore Wurttemberg to Ferdi nand ; and he gave further offence by seeking to secure the suc cession of his son Philip, afterwards king of Spain, to the imperial throne. In 1551 Ferdinand agreed that Philip should be his own successor. Events caused these plans to be dropped, but there was a rift between the brothers. During the short war between the emperor and Maurice, elector of Saxony, in 1552 Ferdinand's atti tude was lukewarm. He negotiated the treaty of Passau with Maurice in 1552, and in 1555 after the conduct of imperial busi ness had virtually been made over to him, and harmony had been restored between the brothers, he was responsible for the religious peace of Augsberg. Early in 1558 Charles abdicated and on March 24, Ferdinand was crowned at Frankfort. The emperor's short reign was mainly spent in seeking to settle the religious dif ferences of Germany, and in efforts to prosecute the Turkish war more vigorously. Although he held firmly to the Roman Catholic Church he sought to obtain tangible concessions to her opponents; but he refused to conciliate the Protestants by abrogating the clause concerning ecclesiastical reservation in the peace of Augs burg, and all his efforts to bring about reunion were futile, though he secured the privilege of communion in both kinds from Pius IV. for the laity in Bohemia and in various parts of Germany. In November 1562 he obtained the election of his son Maximilian as king of the Romans, and died in Vienna on July 25, 1564. His family had consisted of six sons and nine daughters.
Ferdinand sought to consolidate his Austrian lands, reformed the monetary system in Germany, and reorganized the Aulic coun cil (ReitIishofrat). Less masterful but more popular than his brother, whose character overshadows his own, he was just and tolerant, a good Catholic and a conscientious ruler.
See the article on CHARLES V. and its bibliography ; also HUNGARY. F. B. von Bucholtz, Geschichte der Regierung Ferdinands des Ersten (Vienna, 1831-1838) ; K. Oberleitner, Osterreichs Finanzen and Kriegs wesen unter Ferdinand I. (Vienna, 1859) ; E. Rosenthal, Die Behorden organisation Kaiser Ferdinands, I. (Vienna, 1887) ; and W. Bauer, Die Anfdnge Ferdinands I. (Vienna, 1907).