Altstadt Spandau is the historic centre of the Spandau borough in the western suburbs of Berlin, situated on the right bank of the Havel river by its confluence with the Spree tributary. It arose near the site of a former Slavic gord during the German eastward expansion in the early 13th century. A castle at Spandowe, erected on a Havel island to secure the eastern borderlands of the Margraviate of Brandenburg, was already documented in a 1197 deed issued by the Ascanian margrave Otto II.The city itself was first mentioned on 7 March 1232, when the Spandau citizens were vested with further privileges by the Brandenburg margaves John I and Otto III. A first church is documented in 1240; the present-day Saint Nicholas Church was built in the late 14th century. It became the initial point of the Protestant Reformation in Brandenburg, when on 1 November 1539 Elector Joachim II Hector converted to Lutheranism and celebrated the first communion under both kinds here. A Jewish community in Spandau existed since the 13th century, a synagogue is documented since 1342.