A pioneering Victorian Welshman helped spur a change in the way early Olympic athletes started their races.
Monmouth runner Tom Nicholas caused controversy by crouching low and placing his hands on the floor ahead of his favoured 440 yards distance.
But his style won approval from the sport's authorities, leading to the start that is now so familiar to the world.
The story is told in the three-part documentary 'Wales at the Olympics' that runs on BBC One Wales on Tuesdays at 22:35 BST until 17 July. Each show will be available for seven days on BBC iPlayer after transmission.