Dormer windows were inserted into the roof, and a gallery was built into the westernmost bay of the nave, during the 18th century. The gallery is supported on cast iron Doric pillars, encased in wood. The front of the gallery is pannelled, and in the centre is the Royal Arms of George III in 1816. King George III was also head of the House of Hanover, a principality in Germany. Hanover fell to the French and Prussians during the Napoleonic Wars but after the defeat of Napoleon at the Battle of Waterloo, Hanover was elevated to an independent kingdom by the Congress of Vienna. This resulted in a change to the English Royal Arms to reflect George III's changed status. Massive tie-beams add to the structural strength of the building, but severely restrict the view from the gallery.