but the vaults of the aisles of the nave are still of Romanesque type. Relics of the Romanesque walls of the choir, including a bank of stone, can be seen below the arcades around the choir. The outer walls of the ambulatory are originally Gothic, and so are the vaults of the ambulatory. Many details inside the church suggest that the builders followed the example of Laon Cathedral, the construction of which had been started one or two decades before the Gothic reworking of the collegiate church in Limburg. In 1802, during secularisation, the Stift's independence was brought to an end (like many other abbeys and Stifte) and it was given to the Princes of Nassau-Usingen. This seizure took place as part of the German mediatization, in which the House of Nassau received the Stift as compensation for the loss of the County of Saarbrücken on the left bank of the Rhine. After secularisation, the church was used as a parish church. In 1827, at the request of the Duchy of Nassau, the independent Diocese of Limburg was founded. This diocese contained the territory of the Duchy and the free city of Frankfurt am Main, with the bishop's seat in the former collegiate church of St George, which was promoted to the rank of cathedral. The first bishop of Limburg was Jakob Brand (1827–1833). The diocese has currently about 700,000 Catholics and is one of the younger dioceses. On 2 February 2007, Pope Benedict XVI accepted the age-related resignation of former bishop Franz Kamphaus. Franz-Peter Tebartz-van Elst was named new bishop on 28 November 2007, and took office on 20 January 2008. He was suspended on 23 October 2013, he was thereupon general vicar Wolfgang Rösch, who in turn was replaced by Georg Bätzing, who was elected to the office of Bishop by the Cathedral Chapter, confirmed by Pope Francis and Ordained by Arch-Bishop Woelki in 2016, since 2020 he has been Chairman of the German Bishops‘ Conference. Architecture Exterior The cathedral is a three-aisled basilica, which combines late Romanesque and early Gothic elements. It has a narthex at the western end and a semi-circular choir with an ambulatory. The outside measures 54.5 m long, with a width of 35.4 m. The building has a complicated structure; seven spires rise from it. The number seven is a symbolic reference to the number of the sacraments. The tallest of these towers