 For a number of years after 1146 the two cathedrals operated in tandem, with Saint Lazare as the summer cathedral (from Easter to All Saints' Day) and Saint Nazaire as the winter cathedral.The cathedral was finished in 1146, (with the exception of the porch which was added a few years later); Abbé Grivot writing in his excellent guide to the cathedral explains that the interior of the building is not Gothic, as there are no crossed diagonal ribs, but Romanesque vaulting as was used at Cluny III.Saint Lazare was eventually confirmed as the one cathedral of Autun in 1195.