SLovenia
No, the country has split into Serbia, Croatia, Slovenia, Bosnia, Montenegro, Macedonia and Kosovo (disputed).
England
Philippines
Pakistan
Eastern part of Pakistan
Panama , once part of Columbia, is the country.
It's a Commonwealth country because it was once part of the British Empire.
Eritrea was once part of Ethiopa.
Mali.
It was once part of the United Kingdom. It is now and independent country, while Northern Ireland is still part of the United Kingdom.
The Netherlands. Belgium became an independent country on October 4, 1830. Prior to that it has changed hands many times. The Eastern part was once the Bishopric of Liege, which was part of Germany. The western part was once Burgundian, then the 'Spanish Netherlands', then the 'Austrian Netherlands'. Various parts were once French, and during the Napoleonic wars (up to 1815) the whole of what is now Belgium was part of France.
Samoa as a whole was once part of the United States. It is now split into Western Samoa and U.S. Samoa.