Archaeological excavations undertaken between 1995-98 unearthed the remnants of the synagogue of the medieval Jewish community of Vienna which is known today as the "Or Zarua Synagogue", named after the learned Viennese rabbi (Rabbi Isaac Ben Moses Or Zarua). It was erected in the middle of the 13th century and consisted of a freestanding one-room building. It appears that the synagogue was expanded shortly before 1294. A third, rather thorough, rebuilding of the synagogue took place from around the middle of the 14th century onwards. It was extended as far as possible to the east and also the north room was extended to the east and fitted with colorful tile flooring. It is assumed that this north room may have housed the Yeshiva of Vienna. After this extensive rebuilding, the building of the synagogue only underwent some minor changes to its interior furnishings before its destruction in the year 1421. The synagogue covered a total area of about 465 square meters and was one of the largest known medieval synagogues.The few privileged Jews allowed to live in Vienna after the Vienna Gezera (1420) had their own cemetery in the Rossau and also at least one synagogue.
The community leader Veith Munk was allowed to have a public praying room in his house in 1600. Twenty four years later, Emperor Ferdinand II granted the Jews of Vienna the right to have a synagogue with a rabbi in the Sterngasse 6. When the Jews of Vienna were ordered to move to the Untere Werd in 1624 (another district of Vienna - today Leopoldstadt), they had a small community synagogue ("Alte Synagoge") there and a number of small private synagogues. A donation by Zacharias Meyer and his wife enabled the building of a synagogue in the 1650s ("Neue Synagoge"). When the Jews were expelled from Vienna in 1670, the building was converted into a church (1720) and named "Leopoldskirche", in honor of the Habsburg Emperor Leopold I (1640-1705).
The privileged Court Jews who settled in Vienna from the late 17th century and during the18th century were not allowed to found a community or have a public synagogue. They could perform religious services only in private houses. However, the peace treaties between the Ottoman Empire and the Habsburg Monarchy in the first half of the 18th century enabled the permanent settlement of Sephardi Jews in Vienna. As Ottoman subjects protected by the Sultan, they enjoyed freedom of faith in the Habsburg Monarchy. They were able to establish a Jewish community in 1737 and found houses of prayer.
Only in 1811, could the Ashkenazi Jews of Vienna purchase the "Dempfinger-Hof" for religious purposes. They established a synagogue, a school and a ritual bath there. Eventually, in 1824-26, a new synagogue building, fitting the needs of a growing Jewish community, was built in the Seitenstettengasse by the renowned architect Josef Kornhהusel. The appearance of the synagogue had to be that of a regular house, but the interior is a fine example of Central-European synagogue architecture.
The growing number of Jews living in Vienna and the immigration from Eastern Europe made it necessary to build further houses of prayer to meet the needs of various religious and ethnic communities. In the Tempelgasse in the 2nd district, where most of the Jews lived, a central synagogue was built in 1855-58. The "Leopoldstaedter Tempel" was designed by Ludwig Fuerster and had 2,240 sitting and 1,500 standing places. It's design featured oriental elements. The complex also housed a ritual bath, meeting room and lodging for community officials.
The orthodox synagogue in the Grosse Schiffgasse 8 ("Schiffschul") was established in 1864. It was built in a traditional style with 750 sitting places and expressed in the choice of architectural elements its resistance to new trends which the Leopoldstaedter Tempel symbolized.
Further synagogues were built in the suburbs until the 1880s: in Fnfhaus (15th district, Turnergasse 22, 1871/72), Floridsdorf (21st district, 1876/77, Holzmeistergasse 12), Ottakring (16th district, Hubergasse 8, 1885/86) and Wהhring (18th district, Wienerstrasse 39, today Schopenhauerstrasse, 1888/89).
The Sephardi-Turkish community opened in 1887 a prestigious synagogue located at the present day Zirkusgasse 22. It had a capacity of 314 seats for men and 100 upholstered seats in the women's section and another 750 standing places. The yearly celebration to mark the birthday of the Sultan was an occasion that attracted also a great deal of Ashkenazi Jews to the splendid building, but extremely popular was the Simchat Torah holiday whose different liturgy and exotic customs appealed to many.
Synagogues and prayer houses were not only established for praying communities made up of people from the same place of origin; other synagogues were establisherd by associations of various Jewish traders and artisans, like that of the Dienstmaenner ("porters"), who had a synagogue of their own in the Taborstrasse.
The Viennese architect Max Fleischer designed numerous synagogues in Vienna and the Habsburg Empire. Synagogues built according to his planns were located all over Vienna, in the 6th (Schmalzhofgasse 3, 1883/84), 8th (Neudeggergasse 12, 1903) and 9th district (Mllnergasse 21, 1888/89). Many of Fleischer's synagogues were built in a neo-Gothic style, stressing similarity to Christian churches and expressing the assimilationist trends of some of the Jews of Vienna. The only surviving synagogue built by Fleischer is located in the court of the former General Hospital of Vienna (6th court of the complex, Alserstrasse, today on the campus of the University of Vienna).
Wilhelm Stiassny, who also built the synagogue in Wiener Neustadt, did not wish to express assimilation in his work. The synagogue built in the Leopoldsgasse 29 for the Polish community was loaded with decorative elements and its "oriental style" distinguished it clearly from other buildings.
Four Viennese synagogues were built by architect Jakob Gartner: the "Humboldtsynagogue" in the 10th district, in 1898; a synagogue in Simmering (Braunhubergasse 7), 1900; one in the Kluckygasse in the 20th district and the last one in 1908 in the Siebenbrunnengasse (4th district). Gartner preferred Romanesque elements and used towers in his works.
Synagogues with clear references to modernistic developments were built in 1907 in Dצbling (19th district, Dollinergasse 3, Julius Wohlmuth architect) which was in the style of the Jugendstil, in 1911/12 in the Pazmanitengasse 6 (Ignaz Reiser architect) in a modernistic style, and in the inter-war period the synagogue in Hietzing (13th district, Eitelbergergasse 22, Arthur Gruenberger architect) that featured cubistic elements. Ignaz Reiser was responsible for the architectural design of the Jewish part of the Viennese Central Cemetery at Gate 4 where he built, among others, an impressive ceremonial hall in 1926/27.
From the more than a hundred Jewish houses of prayer, very few survived the organized vandalism of the November Pogrom in 1938 (Kristallnacht) and the ensuing anti-Jewish persecutions of the Third Reich. Synagogues, shuls and stiebels were severely damaged, plundered, set on fire and destroyed. The interior of the Seitenstettentempel in the Seitengasse was vandalized, but was not set on fire in order not to endanger the neighboring houses.