Principality of Wales ended in 1282.
Wales is a principality, not a duchy. Prince Charles is the current Prince of Wales.
It's in Wales. I believe 'South Wales' refers specifically to the southernmost part of the principality.
Principality of Sealand was created in 1967.
Principality of Drutsk was created in 1101.
Principality of Salerno was created in 851.
Principality of Orange was created in 1163.
Principality of Göttingen was created in 1279.
Principality of Serbia was created in 1817.
Principality of Beloozero was created in 1238.
Principality of Halberstadt was created in 1648.
Principality of Halych was created in 1124.