National Day of Tonga is celebrated on 4th November. Before 2006, it had been known as Tonga Constitution Day. It commemorates the enactment of the Constitution of the Kingdom of Tonga in November 1875.
Tonga was united into a single kingdom in 1845 by a young warrior Taufa?ahau. In 1831, he was baptized and became known as Siaosi (George). He adopted the name after King George III of the United Kingdom.
Tonga officially became a kingdom on 4th November 1875, when the King enacted the constitution and took the name George Tupou I, King of Tonga. The anniversary of the adoption of the constitution was designated as a public holiday, Constitution Day.
In 1995 Bank of Tonga issued a 1 Pa'anga banknote which depicts the portrait of King Taufa'ahau Tupou IV on the obverse and the view of the countryside on the reverse.
Image Courtesy: banknotes.com