The city of Zürich started life as a Roman customs post by the name of Turicum. Expansion thereafter was slow, but merchants trading in textiles gradually increased the financial clout of the town, and in 1218 it graduated to the status of a free city under the Holy Roman Empire. In 1336 the increasingly powerful merchants and artisans formed guilds that took over the governing of the city.
Zürich's reputation as a cultural and intellectual centre began after it joined the Swiss Confederation in 1351. From 1519 Huldrych Zwingli helped things along with his teachings during the Reformation, and he became a key figure in the running of the city until his death on the battlefield in 1531.
Zürich's intellectual and artistic tradition continued during WWI with the influx of luminaries such as Lenin, Trotsky, Tristan Tzara, Hans Arp and James Joyce. In 1916 the Dada art movement was born in Zürich, with Hugo Ball creating the 'artist tavern' known as Cabaret Voltaire. Around the same time, Carl Jung was honing his psychoanalytical theories in the city.
On the financial side, Zürich's international status as an industrial and business centre is thanks in no small part to the efforts of the energetic administrator and railway magnate Alfred Escher (1819-1882); throughout his life, he was also a strong force in politics. In 1877 Zürich's stock exchange was founded, and it is still the most important in the country.
In recent years, the Social Democrats have dominated municipal politics. They're officially at the helm of Zürich's administration, but the guilds retain a powerful voice in the running of the city, albeit behind the scenes. Zürich remains Switzerland's commercial and financial hub, and the canton is the country's most affluent.