Berlin lies in northeastern Germany, east of the River Elbe, that once constituted, together with the River (Saxon or Thuringian) Saale (from their confluence at Barby onwards), the eastern border of the Frankish Realm. While the Frankish Realm was primarily inhabited by Germanic tribes like the Franks and the Saxons, the regions east of the border rivers were inhabited by Slavic tribes. This is why most of the cities and villages in northeastern Germany bear Slavic-derived names (Germania Slavica). Typical Germanized place name suffixes of Slavic origin are ''-ow'', ''-itz'', ''-vitz'', ''-witz'', ''-itzsch'' and ''-in'', prefixes are ''Windisch'' and ''Wendisch''. The name ''Berlin'' has its roots in the language of West Slavic inhabitants of the area of today's Berlin, and may be related to the Old Polabian stem ''berl-''/''birl-'' ("swamp"). Since the ''Ber-'' at the beginning sounds like the German word ''Bär'' (bear), a bear appears in the coat of arms of the city. It is therefore an example of canting arms.