London's famous Trafalgar Square Christmas tree lit up

Video caption, Watch: Trafalgar Square's tree is switched on for Christmas

The lights of the Trafalgar Square Christmas tree have been switched on in London.

Every year since 1947 Norway has sent a tree to Britain as a thank you for its support during World War Two.

The near-20m-high (65ft) Norwegian spruce, which is about 70 years old, was draped in energy efficient bulbs before being lit up in a ceremony on Thursday evening.

Described as the "world's most famous Christmas tree", it had to have something of a makeover after its 1000-mile long journey from Norway.

Image source, Mayor of Oslo

Image caption, Lord Mayor of Westminster Patricia McAllister (on the left) and Mayor of Oslo Anne Lindboe (on the right) helped to cut down the tree in Oslo, Norway

Earlier this week Westminster City Council said branches were removed from the tree in Norway for transportation, before being reattached in a "branch transplant" as the tree was erected in Trafalgar Square.

Tree surgeons hammered the severed branches back into the tree to give it an appearance and shape more typically associated with a Christmas tree.

The tree will remain in Trafalgar Square until 5 January, when it will be chipped and composted.