A Jewish community in Zürich was first mentioned in 1273, but during the 1349 pogrom the Jewish citizens were banned from Zürich, and the synagogue was repealed. On 25 February 1352 Jewish citizens were allowed to live again within the medieval town walls. In 1363 the so-called "Judenschuol", a medieval term in Zürich for the Synagogue situated at the Neumarkt (Zürich) was mentioned. On 2 November 1383 the Jewish citizens of Zürich were allowed by Heinrich, Bishop of Konstanz, on request of the city council of Zürich to renew the Synagogue and the cemetery, under the reserve that exclusively Jews may be buried who resided (namely Burgrecht) in Zürich. At the location of the former synagogue, a plaque was mounted towards Synagogengasse and Grimmenturm.
The surviving Jewish citizens of the 1349 pogrom, were expelled indefinitely from the city in 1423. Thereafter, the property probably was used from 1455 as an accommodation building, and the Jewish citizens were forbidden to live in the city and in the canton Zürich to 1850, even in the whole area of the today's Switzerland; excluded the two communities in Endingen and Lengnau in the Surb Valley. Among others, Jewish citizens from Endingen and Lengnau, 80 Jewish women, children and men in all, were allowed by the authorities to settle in the whole territory of the Canton of Zurich in 1850, and in 1862 only 175 people, including 100 in the Zürich district. After the repeal of the majoritiy legal restrictions on Jewish citizens, on 29 March 1862 the Israelitische Kultusverein (literal: Israelite Cultus Society) was founded by 12 members. In 1880 its name was changed in the present Israelitische Cultusgemeinde Zürich. As early as in August 1877, the community tried to be accepted as a religious community in the canton of Zürich – the request was denied as "otherwise, other sects might apply for a state contribution." Not as before 2007, the ICZ community got the cantonal acceptance by introducing the accordingly cantonal law on 1 January 2008. As of today, the unified Jewish community of Zürich is the largest Jewish community in Switzerland. Sigi Feigel, Mordechai Piron and Daniel Jositsch are among of the most prominent members of the community.
The library was awarded because of their special content as a Swiss heritage of national importance in 2009. Nevertheless, there were discussions in early 2014 about the future of this cultural heritage for financial reasons. The library of the largest Jewish community in Switzerland owns more than 50,000 volumes in Yiddish, Hebrew and German language. Among these there are, in addition to fiction, valuable scientific works, Judaica, Hebraica, Hebrew prints from the 16th to 18th century, theological literature (Talmudica), prayer books and Bibles.
In December 1939, the Verein Jüdische Bibliothek Zürich (literally: Jewish library Zürich association) handed over its stocks to establish the ICZ library while Jewish libraries in Europe were destroyed by the Nazi regime. After the war, Hannah Arendt, then managing director of the Jewish Cultural Reconstruction, Inc., handed over parts of the library of the Breslau Rabbinical Seminary in Germany which was suppressed by the Nazis. The oldest books of its collection date back to the 16th century, among them a 1595 print of Flavius Josephus' Antiquities of the Jews, a testimony early book printing dating back to 1595.
On occasion of the 75th anniversary of the ICZ library, the anniversary edition Quelle lebender Bücher (literally: source of living books) was published, edited by the ICZ-librarians Yvonne Domhardt and Kerstin A. Paul, in which 75 people present their favorite book from the library. Among them are "Five years in the country Neutralia" by the Ukrainian journalist Shemariah Gorelik, who talks about his stay in Switzerland from 1914 to 1918. Or Johann Caspar Ulrich, who wrote as the first Christian author a veine history of Swiss Jews in the mid-18th-century. The contemporary Swiss writer Charles Lewinsky was inspired by a 1938 edition of the Israelitisches Wochenblatt: the protagonist Felix Grün in Lewinsky's family saga Melnitz. Not only because of the complete volumes of the newspaper Israelitisches Wochenblatt, the ICZ is a rich cultural and historical source for Judaism in Switzerland, its library is a central place of the examination of Jewish identity, and with yourself, the literature professor Andreas Kilcher wrote. The importance of the library was also shown on occasion of the debate on its possible division: The library is full of hidden comments to ourselves. When for financial reasons the sponsorship publicly discussed to outsource the scientific inventory in the Zürich central library, by end of 2014 the Verein für Jüdische Kultur und Wissenschaft (literally: Association for Jewish Culture and Science), however, managed to collect from foundations and private donations the amount of CHF 250,000, and thus ensuring the financing of the library for another three years.
The ICZ provides the second-largest historical archives in the section Jewish contemporary history, right after the records of the Verband Schweizerischer Jüdischer Fürsorgen (VSJF), literally the Association of Jewish Swiss Welfare Services. The rich and diverse archives contains both written and audio-visual media, among them photographs of the ICU presidents and collaborators, sound films, interviews e.g. with Sigi Feigel, speeches of Shimon Peres or Willy Brandt, a 1939 film showing the laying of the foundation stone of the community center allowing a deep insight into Jewish life and work in Zürich. The social section comprises hundreds of personal files and index cards, next to the protocols of the community meetings and the board meetings. Besides that, the records include numerous external contacts, and the political and cultural commitment of the ICZ which verify the community's regional position, as well as on national and international level. Antisemitism, racism, and the examination of WWII are the most important topics in these documents. The extensiveness and the antiquity of the educational and religious material, compared to other documents, show the importance of these tasks to the Jewish community. The first yearbook of religious education, or certificates illustrating the acquisition of land for the community's synagogue date back to the 1880s. On occasion of the 150th anniversary of the ICZ, in June 2012 the indexing of the historical archives of the ICZ was finished. The institutional record group has a volume of 85 running metres, but due to organisational reasons, documents of the rabbinate as well as of the heads and members of many commissions are still under the care of the ICZ.
The religious school was attended by 80 children in 1884, in 1894 there were 130 students, and 18 years later 230. Since 1898, the municipality has its own schoolhouse. The poor relief is governed since 1901.
The community center in Zürich-Enge was modernized in 2010. The social care for the sick and old people, for refugees, and people otherwise in need of help is from its foundation of the main duties of the ICZ.
On 5 July 1865 the Jewish community, which at that time numbered 30 members, mentioned the acquisition of a field for applying a cemetery. On 31 May 1866 it was inaugurated on occasion of the first funeral of a Jewish woman by the Lengnau Rabbi Dr. Meyer Kayserling. In 1892 a cemetery hall was built in the so-called Moorish style. After several expansions, a large second site was bought in 1916, and today the cemetery area comprises 0.17354 hectares (0.43 acres). Since the installation of the second cemetery in 1952, fewer and fewer burials were done at the very first Jewish cemetery in Zürich since the 14th century. Notable interments include Felix Salten (1860-1945), Joseph Schmidt (1904-1942) and Otto Klemperer (1885-1973).
The second ICZ cemetery was inaugurated in 1952 and extended in 1988, and it covers an area of 3.4618 hectares (8.55 acres). At the cemetery grounds there is a large cemetery hall with rooms for ablution (Tahara). The glass windows of the cemetery hall were designed by the Jewish artist Régine Heim-Freudenreich (1907-2004). A memorial stone (limestone cube) by Susi Guggenheim Weil recalls the victims of in the Nazi era. Notable interments include Hermann Levin Goldschmidt (1914-1998), Kurt Hirschfeld (1902-1964), Mascha Kaléko (1907-1975), Erwin Leiser (1923-1996), Albert Pulmann (1893-1965), Jenny Splatter Schaner (1907-1996), Margarete Susman (1872-1966), Lydia Woog (1913-2003), and Sigi Feigel (1921-2004), the former ICZ president.
On 6 July 2015 the ICZ has loosened the funeral arrangements for women. Henceforth, women are allowed at the funeral of a relative or friend of the deceased whose grave and can participate in all burial rites. Previously the related women had to wait along with the rest of the female mourners at the wayside and were not admitted to the grave, at least officially. In reality the presence of women at the grave has been tacitly accepted, but initiated by Chana Berlowitz, the municipal assembly decided a valid determination to change this old tradition. The women are therefore allowed not only to the grave of their relatives or fellow dead, they may also participate in the blades or speak the funeral prayer. In addition, the segregation among the mourners at the funeral chapel was abolished.
The danger for the Jewish community has increased continuously since the 2000s, and since the terrorist attacks on Jewish people in France and Belgium, the risk situation has become even more precarious. According to Swiss security experts, the current investments in security are at best adequate, but compared with France rather modest. Even the French government contributes to the security costs of the French Jewish communitites, while the financial burden in Switzerland is supported solely by the Jewish communities. Because there is no state support for the protection of religious minorities in Switzerland, the municipality must pay for it themselves. Considering that, the Jewish community in Zürich urges government support for the rising security costs. Monitoring personnel, video surveillance and bulletproof windows are among the standard safety measures in Zürich. The security costs are further increased and almost unsustainable for the Jewish communities, the Zürich police chief Richard Wolff said in an interview with the Tages-Anzeiger newspaper. Hence, the Jewish community stands like no other Swiss minorities in the focus of terrorist attacks. Wolff is responding to the demands of Shella Kerész, president of the ICZ, and the city of Zürich should take over half of the safety issues. For years, the Jewish community invested around 800,000 Swiss Francs (CHF) for the protection of their 2,500 community members, and these expenditures would be doubled within two years. In December 2015, a meeting on the situation of the Jewish minority in Switzerland was held in Bern. The main theme of the meeting: the rising need for security. Police chief Wolff said on occasion of a panel discussion that the responsibility for protecting the Jewish fellow citizens the government has to assume responsibility. Even the Federal Department of Defence, Civil Protection and Sport (VBS), established under Guy Parmelin a working group to draw up measures to protect Jewish institutions. There are discussed different options, among them financial monitoring or police or army protection, considering if the Swiss Convention for the Protection of National Minorities (Rahmenabkommen zum Schutz nationaler Minderheiten 1999) may provide the legal legitimacy. The Canton of Zürich, because it is home to the largest Jewish community with around 6,000 members, could serve as a Swiss national model.
The building of the Synagoge Zürich Löwenstrasse is listed in the Swiss inventory of cultural property of national and regional significance as a Class B object of regional importance, the ICZ library in Zürich-Enge at the Arboretum Zürich even as a Class A object of national importance.Alfred Bodenheimer (publisher): Nicht irgendein anonymer Verein ... Eine Geschichte der Israelitischen Cultusgemeinde Zürich. NZZ Libro, Zürich 2012, ISBN 978-3-03823-759-4.
Yvonne Domhardt and Kerstin Paul: 75 Jahre Bibliothek Israelitische Cultusgemeinde Zürich. 75 Jahre Bibliothek der Israelitischen Culturgemeinde Zürich. edition clandestine, Biel/Bienne 2014, ISBN 978-3-905297-58-4.