Cyprus and Malta have formally adopted the euro, the last step to integration in the EU following their entry in 2004.
Hundreds of thousands of currency converters have been sent to Cypriot households and the government has urged traders to round their prices down to avoid contributing to inflation.
Malta, meanwhile, is hoping to become a magnet for hi-tech investment as well as enjoying double-digit growth and a boom in tourism. The Cypriot pound, introduced by the British in 1878, will remain in use until the end of January.
The euro will also become legal tender on the UK’s military bases on the island – the first part of sovereign British territory to adopt the currency.