and retired to Padua to regain his health, d'Este was appointed commander of the troops. After recovering, Arcelli returned to Istria and resumed command, but was wounded in battle and died in July 1421. Taddeo d'Este again took command. He damaged the castle of Sanvincenti to the east of Rovigno. He took the Pietrapelosa castle in Istria in August 1421 and during the next few months defeated the army of Aquileia; Istria became divided between the Republic of Venice and the Habsburg County of Pazin. Although Taddeo d'Este was recognized as the most senior of the commanders after Arcelli's death, he was not officially the leader. By the autumn of 1421 the Venetian republic had imposed economy measures on the army, reducing troop levels to their lowest in a long time, with only 400 cavalry. However, in May 1422 an increase in forces was allowed. Milan, Aquileia, Bologna 1422–1437 By early 1422 the conquest of Istria was complete. Taddeo returned home, retaining some of his men but not engaging in warfare for several years. He used the time to reorganize his estates and to buy houses and land in the Este countryside and the city of Padua. In March 1426 a new conflict broke out between Venice and Filippo Maria Visconti, Duke of Milan. Taddeo was asked to lead a company of 100 lances. He was one of the first to enter the fortress of Brescia when it was captured. When the peace of Ferrara in April 1428 brought temporary peace, for a while Taddeo fought in the service of the Pope, helping with the recapture of Bologna. In 1431 Taddeo d'Este was again fighting for the republic against the Patriarch of Aquileia, who with the encouragement of Milan had raised a force of over 6,000 German and Hungarian troops with which to try to recover part of his former domain. Taddeo was sent to Friuli, where he engaged in defensive actions against superior forces until the main Venetian force arrived and decisively and permanently defeated the patriarch at Rosazzo. In November 1432 Taddeo d'Este was defeated in Lombardy, captured and taken to Milan. He was released in April of the next year in exchange for a huge ransom after peace had been arranged between Venice and Milan. The Venetians confirmed Taddeo as leader of 200 cavalry and gave him command of the garrison of Orzi Nuovi in Lombardy. In