All Bank of Scotland notes bear a portrait of Sir Walter Scott on the front in commemoration of his 1826 "Malachi Malagrowther" campaign for Scottish banks to retain the right to issue their own notes. Bank of Scotland's 2007 redesign of their banknotes are known as the "Bridges of Scotland" series. These notes were introduced on 17 September 2007, and show Scotland's most famous bridges on the reverse side. The "Bridges of Scotland" series is currently being refreshed with the issue of new polymer notes with designs that follow the same basic theme of "bridges". The previous "Tercentenary" series notes are being withdrawn from circulation and replaced with the 2007 series (or polymer series as these are issued), but remain legal currency.