Membership in the European Union has grown by ten members to 25.

Ten new countries have joined the European Union, bringing the EU register to 25 member nations.

Eight of the new members are former eastern or central European countries that had been part of the defunct Soviet empire.

The new additions raise the collective population of the EU from 75 million to 450 million.

The president of the European Commission, Romano Prodi, welcomed the new members in a ceremony held in Brussels Friday, saying their arrival marks the end of the Cold War era.

Cultural performances took place in many of the new member nations' capital cities.

The flags of all 25 EU member nations will be unfurled in a ceremony later on Saturday in Dublin. Ireland currently occupies the EU rotating presidency.