In photos: Britain celebrates Queen Elizabeth II becoming the country's longest-serving monarch
Queen Elizabeth II greets royal supporters on September 9, 2015 as she becomes Britain's longest-serving monarch.
A band of pipers rehearse for a ceremony in Tweedbank on the Scottish Borders.LEON NEAL/AFP / Getty Images
Britain's Queen Elizabeth II attends a ceremony at Tweedbank Station.LEON NEAL/AFP / Getty Images
Britain's Queen Elizabeth II, Prince Philip, Duke of Edinburgh and Scotland's First Minister Nicola Sturgeon attend a ceremony at Tweedbank Station.LEON NEAL/AFP / Getty Images
Britain's Queen Elizabeth II gives an address at Tweedbank Station.LEON NEAL/AFP / Getty Images
Britain's Queen Elizabeth II talks with Prince Philip, Duke of Edinburgh at Tweedbank Station.LEON NEAL/AFP / Getty Images
Britain's Queen Elizabeth II attends a ceremony at Tweedbank Station.LEON NEAL/AFP / Getty Images
Royal supporters wave Union Flags and Scottish Saltires.LEON NEAL/AFP / Getty Images