The bridge is most probably named after Princess Margaret. It would have been an impressive sight in 1503 watching 500 English soldiers marching across to accompany the daughter of Henry VII on her way to meet her future husband James IV of Scotland. She stopped at the very influential Cistercian Abbey at Newbattle to obtain a blessing from the monks before meeting her future husband.
The medieval bridge has changed very little since that time but here there once had been a very important main route from England to Edinburgh. Previously the Romans marched here along Dere Street on the route from Ebaracum (York) to garrisons at Inveresk and Cramond on the eastern end of the Antonine Wall. Later the route from Jedburgh became known as the Royal Way linking England with important ecclesiastic sites of the Scottish Borders so it was the preferred route to Edinburgh. Edward I had crossed the South Esk river here on his way to attack Edinburgh Castle in 1295 and again later when he defeated William Wallace in 1298. Now it is very peaceful with only walkers and golfers crossing the bridge with dogs swimming in the river nearby.