It's an old established Belgian insurance company that set up a UK Division by buying Northern Star Insurance in 2000. It then bought Bishopsgate Insurance and changed its name to Fortis. After the financial crisis it changed its name again to Ageas. It has also set up RIAS, and bought Groupama Insurance and Castle Cover.
As well as offering its own insurance brands, i underwrites insurance for and through retail partners including Post Office and Tesco.
Some of these names you've surely heard of.
It's big.