The Cook Islands Ensign leaves no doubt about its British heritage with the Union Jack so prominent top left. The top left quadrant on a flag is called the ‘canton’.
The blue background represents the sea and the circle of 15 stars represents the 15 islands that make up the Cooks Islands.
Most people have only heard of the main touristy two islands of Rarotonga and Aitutaki. There’s also Penrhyn (aka Tongareva), Rakahanga, Manihiki, Pukapuka (aka Danger), Nassau, Palmerston, Mangaia, Mauke, Atiu (aka Enuamanu), Mitiaro, Takutea, Manuae and Suwarrow islands.
There have been half a dozen flags before this one including the United Kingdom flag and the New Zealand flag. The one before the current design had no Union Jack, a green background and yellow stars.
The collecting and studying of flags, by the way, is ‘vexillology’ and someone who does that is a vexillophile. Funny how everything has a name… the space between the thumb and forefinger is the purlicue… the space between your eyebrows is the glabella… and the groove below your nose and above the middle of your top lip is the philtrum….