When we first met them they were two young impressionable lads from Doncaster and Bradford who could sing a bit.
Now they're mega stars on both sides of the Atlantic who've just taken the Video Music Awards by storm.
They were held last night in LA and Louis Tomlinson and Zayne Malik from boy band One Direction were centre stage.
They won three Moonmen and was a proud night for them and their families. We've be talking to Louis's grandad.