This bridge was built in 1805 and was paid for by George Nugent-Temple-Grenville, the 1st Marquess of Buckingham as a route for the future king George IV from London to his house in Stowe. It replaced a stone bridge next to the Woolpack Inn which was in a bad state of repair. The Marquess did not want it to collapse while the future King was crossing it.
The coat of arms shown here on the side of the bridge is not the only one used by George. Not long after the bridge was built he commissioned Sir John Soane to design an armorial which included 719 quarterings (the average being four) to include all of the families he was descended from, including many Royal or notable families. The resulting piece is 1.4m in diameter!