From 1918 to 1920, the design changed as it became the official American insignia during World War I. Different from the previous emblem, this roundel did not feature a star, but rather three circles.

The roundel was first developed for London Underground a century ago. It is still used by Transport for London today.The roundel is one of the most recognised and imitated logos in the world.

Weavers in east London have celebrated a newly-named stretch of the London Overground by producing a roundel made out of fabric. The soon-to-be Weaver Line, part of the London Overground ...