On Friedl mit der leeren Tasche followed Siegmund der Münzreiche as Prince of Tyrol. Siegmund of Tyrol (1427 - 1496) had the worst possible start to his reign. When his father Frederick died, Siegmund was only 12 years old. He was therefore taken over by his uncle Frederick III, the Emperor of the Holy Roman Empire and father of Maximilian I, into involuntary custody and guardianship. You could say that Siegmund began his career as a hostage of the emperor, his own cousin. Tyrol was now a rich county and the emperor was reluctant to relinquish direct control over it. It was only when the Tyrolean estates protested against this paternalism that Siegmund was able to take office. The Tyrolean Diet had taken over the reins of government in the absence of a sovereign prince, thereby demonstrating its political clout. At the age of 18, Siegmund moved to Innsbruck to take over the official duties. Four years later, he married Eleanor of Scotland (1433 - 1480), the visually unattractive 16-year-old daughter of King James of the House of Stewart. The marriage was to remain childless.

Under Prince Siegmund, there were many innovations on the one hand and a bloated and expensive court on the other. In Innsbruck and the surrounding area, urban life attracted new crafts. In 1453, the princely silver smelter opened in today's Universitätsstraße. In 1484, Siegmund had the mint moved from Meran in South Tyrol to Hall, which earned him the nickname Siegmund der Münzreiche brought in. Two years later, a princely mill was built on the Sill Canal, which was to form the basis for the early industrialisation that developed in the following years. He issued the Schwaz mountain regulations, which was to become the model for all Habsburg mines. Mining officials were given more rights within their sphere of influence, similar to the universities. There were special regulations for miners within society, as they were a highly sought-after labour force. One can speak of an early social and labour law agreement. The miners worked hard, but earned relatively well. The same applied to the mint and the Hall salt works. A wealthy middle class began to emerge.

During his opulent reign, Innsbruck had become a centre of attraction for craftsmen, goldsmiths and artists. The immigrants often came from the aristocracy and did not want to give up their lifestyle in Innsbruck. A special form of metal industry established itself in Mühlau. Plattner created armour and harnesses for noblemen who wanted to present themselves in a manner befitting their status, both on military campaigns and at tournaments. Siegmund was their best customer. He bought a number of tournament armours for himself and as appreciative gifts for aristocrats of foreign courts and guests of honour. The workshops on the Mühlaubach became the leading workshops of their kind in the world. It was not until the 17th century that the richly decorated armour went out of fashion. The city tower near the Old Town Hall as an expression of the city's prosperity and the first parts of the Hofburg were built under Siegmund. A glass painter settled in Innsbruck. The court library grew in step with Siegmund and Eleonore's humanistically scholarly guests. Both were considered art-loving and interested in literature. Before the invention of printing, books were an expensive hobby. Travellers and showmen were also welcome at court to entertain local and international guests.

Siegmund's opulent lifestyle not only cost him a lot of money, but also his political reputation and, at the end of his career, probably also the princely throne. His second marriage was to Katharina of Saxony (1468 - 1524), a lady from a highly aristocratic electoral family. It was probably also thanks to the influence and court behaviour of Siegmund and his two wives that the expenses of the Coin rich auf lange Sicht die Einnahmen aus Steuern, Salinen und den Bergwerken überstiegen. Bei der landesfürstlichen Hochzeit 1484 umfasste allein der Zug der Braut 54 Wagen. Die Gäste mussten in Innsbruck einquartiert und verköstigt werden. Auch mit der 40 Jahre jüngeren Frau war dem mittlerweile senilen Siegmund männlicher Erbe vergönnt, was besonders bitter für ihn gewesen sein muss, betrachtet man die ihm nachgesagten 30 außerehelich gezeugten Kinder. Gleichzeitig wurden die Zeiten rauer für die, die mit dem neuen Lebensrhythmus der Stadt nicht mithalten konnten. Man kann von circa 2000 Stadtbürgern zu dieser Zeit ausgehen. Der Hofstaat Sigmunds bestand aus 500 Personen, der Hofstaat seiner Frau war dabei nicht miteingerechnet. Diese „Fremden“ erregten in Innsbruck Aufsehen. Die Kluft zwischen den sozialen Schichten wuchs und auch die Landstände waren ob des angeschlagenen Staatshaushaltes besorgt. Sein Hof war am Ende seiner Regierungszeit übermäßig aufgebläht und teuer. Ein verlorener Krieg mit den Schweizer Eidgenossen verpflichtete ihn zu Zahlungen, auch ein Krieg mit Venedig endete schlecht. Siegmund musste habsburgische Besitzungen im Elsass und dem heutigen Breisgau an Karl the bold von Burgund, den zukünftigen Schwiegervater Maximilians I. verpfänden. Die österreichischen Vorlande verkaufte er zu einem Spottpreis an das Herzogtum Bayern, die Tiroler Silberbergwerke verpfändete er an Jakob Fugger. Die bayerischen Wittelsbacher wollten über einen Erbvertrag mit dem altersbedingt geistig umnachteten Sigmund auch Tirol wieder unter ihre Kontrolle bringen. Erst kaiserlicher Druck und das eilige Einschreiten der Tiroler Landstände und Maximilians ermöglichten den Verbleib des Landes beim Haus Habsburg. 1490 übernahm er das Amt des Landesfürsten, obwohl Siegmund noch am Leben war. Damit waren die gesamten Erblande des Hauses Habsburg wieder in einer Hand. Siegmund war nicht der erfolgreichste Landesherr Tirols, genießt dank seiner im Stadtbild gut sichtbaren Verdienste rund um Innsbrucks kulturellen Aufstieg aber noch immer Ansehen in der Volksseele.