The Cook Islands flag, officially called the Cook Islands Ensign, features a blend of the Cook Islands and the United Kingdom. The current flag design is based on the traditional design for former British colonies in the Pacific Ocean. The flag has a deep blue background (ensign). In the upper left corner, there is the Union Flag, ensign of the United Kingdom. To the right there are 15 white stars in a circle. The blue in the flag is symbolic of the ocean and the peaceful nature of the inhabitants. The Union Flag is a historic tie to its period as a protectorate, and the 15 stars are symbolic of the 15 islands that compose the Cook Islands.
The evolution of the flag runs parallel to the history of the Cook Islands. From 1858 to 1893, the Cook Islands were known as the Kingdom of Rarotonga, one of the islands within the modern day Cook Islands, and were an independent nation. In 1888, the Kingdom of Rarotonga became a protectorate of the United Kingdom, at its own request, and for the first time the Union Flag was represented on the flag. In 1893, the Kingdom of Rarotonga officially changed its name to the Cook Islands, and the flag was denoted with a palm tree within the Union Flag. Between 1901 and 1902, Cook Island used the Union Flag as its ensign. After the Cook Islands were absorbed into the redefined colony boundaries of New Zealand in 1902, the Cook Islands used New Zealand’s flag as their own until 1973.
Interestingly, all of the Cook Islands flag iterations were remarkably similar, always featuring the Union Flag (after becoming a protectorate of the United Kingdom). However, between 1973 and 1979, the Cook Islands adopted a green ensign. The green represented the continuous growth and life on the islands. The same 15 stars were emblazoned on the flag in a circular pattern to the right of the flag, but were changed to yellow. The yellow stars represented faith, love, happiness, and commitment shown by the islanders, while the circle was a representation of the union of the 15 islands. This flag was used until 1979 when the current Cook Islands flag described above was adopted.