Symbol of friendship

The 60th annual Christmas gift of a massive Norwegian spruce for London's Trafalgar Square is on the way, and this year's ceremony aims to guarantee the tradition endures.
Schoolchildren attending the felling ceremony rush to count the rings and check the age of this year's tree.
The three is one hundred years old and 26 meters (85.3 feet) high.
The annual Christmas tree for downtown London is Oslo's tribute to the help extended to Norway by the English during the Second World War. This is the 60th time a Norwegian spruce will grace the city.

Christmas Tree from Oslo to London

A majestic fir tree from the forest outside Oslo began a sentimental journey to London on Friday, where it will do service as the city's Christmas Tree in Trafalgar Square.
It's the 59th year in a row that Oslo has supplied London with a towering Christmas tree for outdoor display. The tree-tradition started shortly after World War II ended.
You can ask just about anyone you like in London, and they will know the tree is a gift from Norway and Oslo.
I think Rotterdam and Antwerpen gets a tree as well.
Norwegian (Old article)