Nicholas fled to Todi in the Papal States, but fell ill and died in 1464, before the archduke surrendered in order to receive the papal pardon. In 1469, Sigismund sold several of his Swabian lands on the Rhine river, including the Alsace landgraviate, the County of Pfirt (Ferrette), the Breisgau and further cities, to the Burgundian Duke Charles the Bold. Sources are unclear, whether he sold them due to his debts he had accumulated owing to his luxurious lifestyle, or just "rented" them because he wanted to have them protected better against the expansion of the Swiss Confederacy. In turn, he extended his Vorarlberg possessions, purchasing the County of Sonnenberg in 1474 and, together with the Swiss (with whom he had concluded a peace treaty in Konstanz) and the Alsatian cities, he sided against Duke Charles of Burgundy in the Battle of Héricourt. In 1477, his cousin Frederick, crowned Holy Roman Emperor in 1452, elevated him to Archduke. Three years later, Princess Eleanor died, and in 1484, Sigismund married the 16-year-old Catherine of Saxony, daughter of the Wettin duke Albert III of Saxony. He had no offspring from either marriage. In the later years of the 1470s and early 1480s Sigismund issued a decree that instituted a radical coinage reformation that eventually led up to the creation of the world's first really large and heavy silver coin in nearly a millennium, the guldengroschen, which the Habsburgs in Bohemia developed later into the thaler. This coin was the ancestor of many of the major European coin denominations to come later and also of the US dollar. Using new mining methods and technology, the largely quiescent silver mines in Tirol were brought back into production and soon numerous surrounding states were re-opening old mines and minting similar coins. This production of large coinage exploded as silver from Spain's colonies in the Americas flooded the European economy. It is from these reforms in part that Sigismund acquired the nickname of der Münzreiche, or "rich in coin". Sigismund was easily swayed by the bad advice of his council and in March 1487 entered into a pointless war with the Republic of Venice, sometimes called the War of Rovereto. Tyrolean forces quickly seized silver mines in the Valsugana valley owned by Venice, and in April 1487 Sigismund outraged Venice further when he imprisoned 130 Venetian merchants traveling to the fair at Bozen (modern Bolzano) and