Crowds gathered at London's Kings Cross station this morning to watch one of the world's most famous steam locomotives set off on its official return to the rails.

The Flying Scotsman is making the journey from London King's Cross station to York, where it will go on display at the National Railway Museum.

It's taken ten years and £4 million to restore the locomotive.

Thousands of people are expected to watch the train along the route from London to the National railway Museum.

Many passengers paid up to £450 for a ticket to travel on the train.