In many ways, the 19th century was a OTL Britain-wank. The challenge here is to continue that well into the 20th, and ideally 21st, centuries; have Britain remain in its place as the world's premier power, either via keeping the empire intact, expanding it, or some other means. What might the world, and Britain, look like today?
An obvious starting point is avoiding the World Wars, but especially a second one if the first still occurs.
An obvious starting point is avoiding the World Wars, but especially a second one if the first still occurs.