 These first appeared in France in the early 11th century in churches that have broad ribs reinforcing a barrel vault.They are also seen at Lisbon and Speyer Cathedrals, Santiago de Compostela and la Madeleine Vezelay in conjunction with groin vaults, as well as at the three Norman cathedrals of East Anglia, of which Peterborough and Ely retain wooden ceilings, while Norwich was not vaulted until the 15th century.The admission of light to the building through a multiplicity of windows was an important element in England.