Possible Clues:

• Polynesian monarchy, member of the Commonwealth
• Island nation where the tau'olunga is performed
• Land in Eton garden
• Sovereign state of Georgia supporting great weight
• Country ruled only by kings named Tupou since 1845
• Pacific Island nation
• Country of more than 170 islands
• Barman is not retiring to overseas foreign kingdom
• Its capital is Nuku‘alofa
• Nation SE of Fiji