The Hussite Wars
In the early months of 1420, Konrad IV met with other Silesian princes in the Silesian Sejm in Wrocław and paid homage to Emperor Sigismund. He then accompanied the emperor to Prague, where Sigismund was crowned king of Bohemia. Konrad IV remained loyal to the House of Luxembourg even after the loss of the German Kingdom, retaining authority only over Silesia. He helped organize a campaign against crime in the Silesian lands, which resulted in the occupation of Broumov.
In recognition of his contributions, the Emperor appointed Konrad IV to Governor of Silesia with the official responsibility of organizing the fight against the Hussites in 1422.
In January 1423, Konrad IV participated in negotiations for a possible alliance between Emperor Sigismund and the Teutonic Order against King Władysław II of Poland. The agreement provided for territorial gains for the Silesian princes in the event of a Polish defeat. However, the treaty was not honored, as King Władysław II received the Emperor's refusal to join the alliance after their meeting at Kežmarok. Following the example of his sovereign, in April 1424, Konrad IV restored relations with Poland and joined his brother Konrad V in Kalisz.
In 1425, Konrad IV led a new crusade, organized by the Kingdom of Bohemia against the Hussites, which was ultimately unsuccessful.
Beginning in 1427, the Hussites retaliated against the allies of Emperor Sigismund with a series of military expeditions. During these campaigns they devastated Lusatia, Złotoryja and Lubań.
To counter the Hussite threat, the Silesian princes and several major cities, including Wrocław and Świdnica, sought mutual aid from Konrad IV and offered him leadership of the coalition. The fear of these cities and princes became evident the following year when a Hussite army led by Prokop the Great invaded Silesia. Most of the princes made deals with Prokop, guaranteeing the safety of their estates in exchange for a substantial ransom and unimpeded passage through their territories.
Despite the treachery of some princes, Konrad IV chose to fight, supported by a contingent led by Duke Jan of Ziębice. The Battle of Stary Wielisław near Nysa took place on 27 August 1428. The coalition forces were decisively defeated, resulting in the death of Duke Jan of Ziębice. However, Konrad IV managed to escape.
After the battle, Prokop's army devastated large parts of Lower and Upper Silesia, particularly targeting the possessions of the Bishopric of Wrocław. In search of protection, Konrad IV forged a closer alliance with Duke Bolko V of Opole, one of the most prominent Hussite leaders among the Silesian princes.
In the following years, despite the defeat of 1428, Konrad IV continued to wage war against the Hussites in Silesia, receiving support from the majority of the Wroclaw nobility.
In 1430, a new Hussite expedition, supported by the Polish mercenary Sigismund Korybut, advanced from the northwest. As a result, Konrad IV lost two important fortresses, Niemcza and Otmuchów, which he regained five years later by buying them from Hussite commanders.
In 1432, Konrad IV's own Duchy of Oleśnica, including the monasteries of Lubiąż and Trzebnica, suffered severe damage when Oleśnica itself was burned.
In 1433, in order to protect the property of the Church, Konrad IV decided to revive the Union of Silesian Princes (Związek książąt śląskich) and once again assumed the position of its leader.
