During the Middle Ages Fürth was jointly governed by the city of Nuremberg, the bishop of Bamberg and the count of Ansbach. Therefore Fürth's coat of arms shows a cloverleaf. Fürth is also older than Nuremberg, dating back to November 1007. See "1000 Jahre Fürth" at http://www.1000-jahre-fuerth.de (German only). Fürth had a large Jewish population before the Nazis expelled and/or murdered them (Levi's founder Levi Strauss for example, also Henry Kissinger, who was born in Fürth and fled to the USA when the Nazis came to power).
As is often the case with cities that close to each other Nuremberg and Fürth enjoy a fierce rivalry that is even more pronounced in soccer, with both teams being dominant in Germany for most of the 1920s. While there is not much love lost between the two cities today, attitudes (outside of soccer games) are more relaxed now than they seem at first glance and the rivalry is mostly folklore.