Taddeo d ' Este Taddeo d ' Este ( ca . 1390 – 21 June 1448 ) was a " condottiere " , a freelance military leader , who was known for his defense of the Republic of Venice in 1439 against Milanese forces under Niccolò Piccinino . Unlike many other " condottieri " of the day , who often changed sides , he served Venice almost exclusively throughout his thirty - year military career . During most of this period Venice was constantly at war with one or more of the neighboring states in northern Italy . Early years . Taddeo d ' Este was born around the last decade of the fourteenth century in Este , the second son of Obizzo II d ' Este , of the younger branch of the family that ruled Ferrara . His mother belonged to the noble family of Collalto . Taddeo became a mercenary at an early age , fighting for Venice , and gave the republic his loyalty for the next thirty years during the wars in which the city struggled to gain territory in the " Terraferma " , on the mainland . However , he was never given independent command for any length of time . Friuli and Istria 1414 – 1422 . Taddeo d ' Este was active in the struggle for territory between Venice and the Patriarch of Aquileia . In 1414 Taddeo led a squad of fifteen lances ( cavalrymen ) in a fight at Zadar against the armies of Sigismund of Luxembourg . The next year he was given permission to return to Este to look after family affairs , since his father had just died . When the truce with Sigismund broke down , in April 1417 he was sent back at the head of 50 lances . In September 1418 he was leading a force of 70 lances in the village of Brugnera , a defensive position along the Treviso - Udine line . In November 1419 , with 100 horsemen , he was sent to defend Cividale del Friuli against Hungarian troops under Louis of Teck , the Patriarch of Aquileia . He organized the defense successfully , then managed to break out and defeat the Hungarians in open battle . By the end of the month he was able to raise the Venetian banner over the castles of Gorizia and Duino . By June 1420 most of Friuli had been conquered and another truce had been arranged with Sigismund . Taddeo returned on leave to Venice and in September married Magdalene , daughter of Filippo Arcelli , governor general of the Friuli army . He was required to return to Friuli immediately after his marriage . In January 1421 he was dispatched to Istria . When Arcelli became ill 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 partiarch 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 May 1434 his son Bertoldo was born , destined to follow in his father ' s footsteps as a soldier for Venice . In August 1434 Taddeo d ' Este was engaged in fighting in Romagna with the troops of Bologna , and was taken prisoner , being released after the intervention of the Marquess of Ferrara . In March 1435 he was given the task of foiling an attempt by Marsilio da Carrara to capture Padua . After he had succeeded , in April 1435 he was admitted to the ranks of the Venetian nobility , with his children and heirs , and admitted to the Great Council of Venice . The Venetians awarded him a palace in their city of Padua . Final decade 1438 – 1448 . In 1438 war with Milan broke out again . Taddeo d ' Este and Francesco Barbero conducted a long and gallant defense of Brescia against Milanese troops under Piccinino . Gattamelata broke out , making a skilled escape via mountain routes , leaving Taddeo with just 1 , 000 men to conduct the defense . The siege of Brescia lasted until December 1438 , when Gattamelata made a feint that drew Piccinino away . The fighting continued , and in September 1439 d ' Este was forced to surrender to greatly superior forces and was imprisoned in Peschiera . In 1441 d ' Este was back in Venice attending the celebrations of the marriage of Jacopo , son of Doge Francesco Foscari . In the Piazza San Marco his company competed for lavish prizes in lengthy tournaments with the companies of the " condottieri " Francesco Sforza and Gattamelata . His first wife having died , he married again in 1442 to Margherita Pio . In the 1440s Leonello and Taddeo d ' Este were challenged by the canons of S . Giacomo , Monselice , who claimed they had been levying tithes in the parish of S . Maria , Solesino , by force for several years . In June 1443 Taddeo d ' Este was commanded to take his company of 800 cavalry to Ravenna , where he placed himself under the command of Francesco Sforza , then serving as captain general of the anti - Papal league . In June 1445 , acting as commander of the army but without the formal title , Taddeo was sent to Bologna with 1 , 000 cavalry and 400 infantry . The next year he managed to arrange for a part of the Bolognese forces to transfer to Venice , and after some further fighting was able to bring the war with Bologna to a close . He then had to return to Lombardy where a renewed struggle with Milan had began . In 1447 d ' Este seized and held Piacenza for Venice . He defended the town with 2 , 000 lances , 2 , 000 infantry and 6 , 000 armed citizens . The town was besieged by Milanese forces under Francesco Sforza . In addition to Sforza ' s men the Milanese army had 10 , 000 soldiers and the " condottieri " under leaders such as Francesco Piccinino , Guidaccio Manfredi , Ludovico dal Verme and others had 15 , 000 cavalry and infantry . The walls were broken down by cannon fire , and flooding of the river Po meant that boats could approach the city walls . After fierce fighting , Taddeo d ' Este , Alberto Scotto and the Venetian governor Gherardo Dandolo were forced to surrender and were taken captive . The town was thrown open to pillage and the inhabitants were treated with great cruelty . Due to his personal friendship with Sforza , d ' Este was soon released . Taddeo d ' Este died suddenly while attempting to take Mozzanica on 21 June 1448 . His state funeral was held in Brescia . His body was returned to Este , where it was buried in the family tomb in the church of S . Francesco . His male line died out in 1463 .