Croatia is embarking on a historic year as it joins the EU's border-free Schengen zone and it ditches its own currency, the kuna, adopting the euro.

The country committed to joining the eurozone when it became the EU's newest member in 2013. Nationalist parties wanted to keep the kuna, but were overruled by the constitutional court.

It is the twenty-seventh country in the Schengen area, which allows 400 million to move freely between countries.

European Commission President Ursula von der Leyen hailed the changes as "two immense achievements" for the youngest member state of the EU.

She said 1 January - when the changes officially happened - would be a day "for the history books". Above all, this would be a moment of "joy and pride for the Croatian people", she said.