British Empire in World War II
When the United Kingdom declared war on Nazi Germany in September 1939 at the start of World War II, it controlled to varying degrees numerous crown colonies, protectorates, and India. It also maintained strong political ties to four of the five independent Dominions—Australia, Canada, South Africa, and New Zealand—as co-members (with the UK) of the British Commonwealth.
Source: Wikipedia — British Empire in World War II (CC BY-SA 4.0)