thumb|Tonga flags flying above a ceremonial gate to celebrate the coronation of [[Tupou VI]]
The national flag of Tonga consists of a red field with a white canton charged with a red couped cross. Adopted in 1875 after being officially enshrined into the nation's constitution, it has been the flag of the Kingdom of Tonga since that year. The constitution stipulates that the national flag can never be changed.
History
The British first arrived in Tonga in the late-18th century, when Captain James Cook made three visits to the islands between 1773 and 1777. Approximately fifty years later, English Wesleyan Methodist missionaries came to Tonga and began converting its people to Christianity. In 1831, they succeeded in converting "paramount chief" Taufa'ahau Tupou,
Upon his accession to the throne, the king sought to design a new flag for the nation, He befriended Shirley Waldemar Baker – a member of the United Kingdom's Tongan mission who later became the Prime Minister of Tonga – and they worked together to formulate a new flag, coat of arms and national anthem for Tonga.
Design
Symbolism
The colours and symbols of the flag carry cultural, political, and regional meanings. The red couped cross alludes to Christianity, It is one of 28 national flags to contain overtly Christian symbols. The white epitomizes purity,