Euro banknotes a common theme of European architecture in various artistic eras. The obverse of the banknote features windows or gateways while the reverse bears different types of bridges. The architectural examples are stylised illustrations, not representations of existing monuments. All the notes of the initial series of euro notes bear the European flag, a map of the continent on the reverse, the name "euro" in both Latin and Greek script (EURO / ΕΥΡΩ) and the signature of a president of the ECB, depending on when the banknote was printed. The 12 stars from the flag are also incorporated into every note.
Euro banknotes and in 2002 notes and coins began to circulate. It rapidly took over from the former national currencies and slowly expanded around the rest of the EU. In 2009, the Lisbon Treaty formalised the Euro's political authority, the Euro Group, alongside the European Central Bank. Slovenia joined the Eurozone in 2007, Cyprus and Malta in 2008, Slovakia in 2009, Estonia in 2011, Latvia in 2014 and Lithuania in 2015. There are seven different denominations of the euro banknotes: €5, €10, €20, €50, €100, €200 and €500. Each has a distinctive colour and size. The designs for each of them have