Frederick IV, Duke of Austria, known as the Tascavuota born in Innsbruck, was the progenitor of the Tyrolean line of the Habsburgs. It is one of the most famous figures of the Tyrolean Middle Ages.
As soon as he came to the government he had to confront the revolt of the canton of Appenzell: it was Leopold IV of Habsburg to charge him with an expedition against them. Frederick recruited a large contingent, consisting mainly of Swabian nobles and contingents made available by cities governed by the Habsburgs (among them the main one was Constance, as well as by imperial cities, their allies), but the expedition did not succeed. Frederick was defeated in battle near Gais, June 17, 1405. Emboldened by their success, in the following two years the rebels made raids in the Inn Valley, sowing terror among the nobles and gathering great sympathy among the peasants. 1408 were defeated in Bregenz by an army composed of Swabian nobles belonging to the League of St. George and contingents made available by the bishop of Augusta.After the defeat the Swiss withdrew from the Tyrol and returned to their territory of origin .
In those same years, Frederick also had to face the opposition of the Tyrolean nobles, who expressed himself with the formation of the League of the elephant (1406) and the League of the Falcon (1407), both inspired by the most powerful of the nobles of Tyrol, Henry VI of Rottenburg, who, not too secretly, aimed at ousting Frederick from the Tyrolean government, even relying on Prince George of Liechtenstein, the bishop of Trent. It was from these enemies that he was nicknamed Tascavuota, a nickname which, however, earned him greater popularity.
In 1407 in various areas of Trentino, and particularly in Val di Non, a series of peasant revolts broke out, while the city and the nobles of Trento turned against the bishop of Moravian origin headed by the "captain of the people" Rodolfo Belenzani. Federico took the opportunity to intervene, driving George von Liechtenstein from the city.
In 1410 Duke Federico had fierce clashes with Henry VI of Rottenburg, who welcomed the Bavarians into his territories. Hard fights with these troops occurred in the lower valley of the Inn. After an armistice, Federico besieged many castles of the Rottenburg (among others Castel d'Enna and Castel Laimburg). In the end, Federico managed to arrest Enrico, who died immediately after his release the following year.
In a series of military operations against Venice (1413) he managed to conquer the Valsugana, although he was then forced to yield to the Serenissima Rovereto and various castles of Vallagarina.
In 1415 Duke Federico was put in serious trouble by his alliance with the antipope John XXIII, to whom he provided help to escape from the Council of Constance. This led to the emperor Sigismund promulgating a ban on him, which led to the sale of much of the Aargau to the Swiss confederates.
Frederick, however, leaning on the peasants, managed to get the better of the Emperor, the neighbors of the Tyrol and his internal enemies. In exchange for this support, the function of the courts was inserted into the county system. Federico also transferred the capital of Tyrol from Merano to Innsbruck.
In 1425 the position of Federico was consolidated, and the Tyrol, thanks also to the discovery of silver veins in Schwaz and Colle Isarco, experienced a period of great prosperity.