Zurich has been continuously inhabited since Roman times. The vicus of Turicum was established in AD 90, at the site of an existing Gaulish (Helvetic) settlement.

Gallo-Roman culture appears to have persisted beyond the collapse of the Western empire in the 5th century, and it is not until the Carolingian period. A royal castle was built at the site of the Lindenhof, and monasteries are established at Grossmünster and Fraumünster.

Political power lay with these abbeys during medieval times, until the guild revolt in the 14th century which led to the joining of the Swiss Confederacy. Zurich was the focus of the Swiss Reformation led by Huldrych Zwingli, and it came to riches with silk industry in Early Modern times.

Early history Prehistoric pile dwellings around Lake Zurich

Numerous lake-side settlements from the Neolithic and Bronze Age have been found, such as those in the Zürich Pressehaus and Zürich Mozartstrasse. The settlements were found in the 1800s, submerged in Lake Zurich. Located on the then swamp land between the Limmat and Lake Zurich around Sechseläutenplatz on small islands and peninsulas in Zurich, prehistoric dwellings were set on piles to protect against occasional flooding by the Linth and Jona. Zurich–Enge Alpenquai is located on Lake Zurich lakeshore in Enge, a locality of the municipality of Zurich. It was neighbored by the settlements at Kleiner Hafner and Grosser Hafner on a then peninsula respectively island in the effluence of the Limmat, within an area of about in the city of Zurich. As well as being part of the 56 Swiss sites of the UNESCO World Heritage Site Prehistoric pile dwellings around the Alps, the settlement is also listed in the Swiss inventory of cultural property of national and regional significance as a Class object.

Oppidum Zurich-Lindenhof

In 2004, traces of a previously unknown pre-Roman Celtic (La Tène culture) settlement were discovered, the center of which lay on the Lindenhof hill respectively the area around the Münsterhof square besides the Limmat. The Celtic Helvetians had a settlement when they were succeeded by the Romans, who established a custom station here for goods going to and coming from Italy. At the later Vicus Turicum, probably in the first 1st century BC or even much earlier, the Celts settled at the Lindenhof Oppidium. In 1890, so-called Potin lumps were found, whose largest weights at the Prehistoric pile dwelling settlement Alpenquai. The pieces consist of a large number of fused Celtic coins, which are mixed with charcoal remnants. Some of the 18,000 coins originate from the Eastern Gaul, others are of the Zurich type, that were assigned to the local Helvetii, which date to around 100 BC.Keltisches Geld in Zürich: Der spektakuläre «Potinklumpen». Amt für Städtebau der Stadt Zürich, Stadtarchäologie, Zurich October 2007. There's also an island sanctuary of the Helvetii in connection with the settlement at the preceding Oppidi Uetliberg on the former Grosser Hafner island.Beat Eberschweiler: Schädelreste, Kopeken und Radar: Vielfältige Aufgaben für die Zürcher Tauchequipe IV. In: NAU 8/2001. Amt für Städtebau der Stadt Zürich, Denkmalpflege und Archäologie Unterwasserarchäologie / Labor für Dendrochronologie. Zurich 2001. at the Sechseläutenplatz on the effluence of the Limmat on Lake Zurich lake shore.

A female who died in about 200 BC found buried in a carved tree trunk during a construction project at the Kern school complex in March 2017 in Aussersihl. Archaeologists revealed that she was approximately 40 years old when she died and likely carried out little physical labor when she was alive. A sheepskin coat, a belt chain, a fancy wool dress, a scarf and a pendant made of glass and amber beads were also discovered with the woman.

Turicum

The Roman Vicus Turicum first belonged to the province of Gallia Belgica, and to Germania superior from AD 90. Following Constantine's reform of the Empire in 318, the border between the praetorian prefectures of Gaul and Italy was just east of Turicum crossing the Linth between Lake Zurich and Walensee. Roman Turicum was not fortified, but there was a small garrison at the tax-collecting point, set up not exactly on the border, but downstream of Lake Zurich, where the goods entering Gaul were loaded onto larger ships. South of the castle, at the location of the St. Peter church, there was a temple to Jupiter. The earliest record of the town's name is preserved on a 2nd-century tombstone found in the 18th century on Lindenhof, referring to the Roman castle as "STA(tio) TUR(i)CEN(sis)".

The area was Christianised along with the rest of the Roman Empire, during the 4th century. According to legend, saints Felix and Regula were executed at the location of the Wasserkirche in 286.

The Alamanni settled in the Swiss plateau from the 5th century, but the Roman castle persisted into the 7th century. The earliest manuscript mention of the settlement, as castellum turegum, describes the mission of Columban in 610. An 8th-century list of toponyms from Ravenna mentions Ziurichi. There is a legendary account of an Alamannic duke Uotila residing on, and giving his name to, the Uetliberg.

Holy Roman Empire

Zurich was part of Frankish-ruled Alemannia from 746, following the blood court at Cannstatt, lying in the Turgowe (Thurgau) dominated by Konstanz.

A Carolingian castle, built on the site of the now ruined Roman castle by the grandson of Charlemagne, Louis the German, is mentioned in 835 ("in castro Turicino iuxta fluvium Lindemaci"). Louis also founded the Fraumünster abbey on 21 July 853 for his daughter Hildegard. He endowed the Benedictine convent with the lands of Zurich, Uri, and the Albis forest, and granted the convent immunity, placing it under his direct authority.

In the wake of this, during the 9th century, Zurich gradually acquired the characteristics of a medieval city. It was now the center of the separate county of Zürichgau, detached from the older county of Thurgau. The early city was dominated by the Fraumünster convent. In 1045, King Henry III granted the convent the right to hold markets, collect tolls, and mint coins, and thus effectively made the abbess the ruler of the city.

The Frankish kings had special rights over their tenants, were the protectors of the two churches, and had jurisdiction over the free community. In 870 the sovereign placed his powers over all four in the hands of a single official (the Reichsvogt), and the union was still further strengthened by the wall built round the four settlements in the 10th century as a safeguard against Saracen marauders and feudal barons.

Zurich became reichsunmittelbar (direct control of the emperor) in 1218 with the extinction of the main line of the Zähringer family. A city wall was built during the 1230s, enclosing 38 hectares (about 94 acres). The Bahnhofstrasse marks the course of the western moat, Hirschengraben marks the eastern moat. The earliest citizens' stone houses at the Rennweg date to this period, using the dilapidated Carolingian castle as a quarry. Emperor Frederick II promoted the abbess of the Fraumünster to the rank of a duchess in 1234. The abbess assigned the mayor, and she frequently delegated the minting of coins to citizens of the city.

The Reichsvogtei passed to the counts of Lenzburg (1063–1173), and then to the dukes of Zahringen (extinct 1218). Meanwhile, the abbess of the Benedictine Frau Münster had been acquiring extensive rights and privileges over all the inhabitants, though she never obtained the criminal jurisdiction. The town flourished greatly in the 12th and 13th centuries, the silk trade being introduced from Italy.

In 1218 the Reichsvogtei passed back into the hands of the king, who appointed one of the burghers as his deputy, the town thus becoming a free imperial city under the nominal rule of a distant sovereign. The abbess in 1234 became a princess of the empire, but power rapidly passed from her to the council which she had originally named to look after police, but which came to be elected by the burghers, though the abbess was still the lady of Zurich. This council (all powerful since 1304) was made up of the representatives of certain knightly and rich mercantile families (the patricians), who excluded the craftsmen from all share in the government, though it was to these last that the town was largely indebted for its rising wealth and importance.

Predigerkirche was built in 1231 AD as a Romanesque church of the then Dominican Predigerkloster nearby the Neumarkt and the city's hospital. As the other convents in Zurich, it was abolished after the Reformation in Switzerland.

In October 1291 the town made an alliance with Uri and Schwyz, and in 1292 failed in a desperate attempt to seize the Habsburg town of Winterthur. After that Zurich began to display strong Austrian leanings, which characterize much of its later history. In 1315 the men of Zurich fought against the Swiss Confederates at the Battle of Morgarten.

The Codex Manesse, a major source of medieval German poetry, was written and illustrated in the early 14th century in Zurich. Among the collection are poems by Süsskind von Trimberg. Very little is known about Süsskind, but scholars speculate that he was a Jew, as the name “Süsskind” was only given to Jews at the time. The first official mention of Jews in Zurich was in 1273. The existence of a synagogue in the 13th century testifies to an active Jewish community. When the Black Death epidemic came to Switzerland in 1348/49, the Jews were widely accused of having poisoned wells. On 23 February 1349, the Jewish men of Zurich were burned, while the women and children were driven from the city. Jewish property was confiscated by the city authorities.

From 1354, Jews began to re-settle in Zurich, but from 1400, the legal situation of Jews in Zurich began to deteriorate. A 1404 law forbade them from testifying against Christians in court, and in 1423 they were indefinitely expelled from the city.

In the later medieval period, the political power of the convent slowly waned. The beginning of self-government came with the establishment of the Zunftordnung (guild laws) in 1336 by Rudolf Brun, who also became the first independent mayor, i.e. not assigned by the abbess. From this time, the city increasingly came under the domination of the Zünfte, a process only fully completed in the 16th century with the suspension of the monasteries following the Reformation. Jews were excluded from the guilds, which were based on the concept of Christian brotherhood.

Under the new constitution (the main features of which lasted till 1798) the Little Council was made up of the burgomaster and thirteen members from the Constaffel (which included the old patricians and the wealthiest burghers) and the thirteen masters of the craft guilds, each of the twenty-six holding office for six months.

The Great Council of 200 (really 212) members consisted of the Little Council, plus 78 representatives each of the Constafel and of the guilds, besides 3 members named by the burgomaster. The office of burgomaster was created and given to Brun for life. Out of this change arose a quarrel with one of the branches of the Habsburg family, in consequence of which Brun was induced to throw in the lot of Zurich with the Swiss Confederation (May 1351).

The double position of Zurich as a free imperial city and as a member of the Everlasting League was soon found to be embarrassing to both parties. In 1373 and again in 1393 the powers of the Constafel were limited and the majority in the executive secured to the craftsmen, who could then aspire to the burgomastership. Meanwhile, the town had been extending its rule far beyond its walls, a process which began in the 14th, and attained its height in the 15th century (1362–1467).

Old Swiss Confederacy