In 1230 Châlons Cathedral was wrecked by lightning. Its reconstruction began with the choir, under Bishop Pierre de Nemours, whose brothers were building-prelates at Noyon, Paris, and Meaux. In 1250 work on the nave was going on, and at the end of the century was built the transept's excellent north façade. The XVII century erected the unsuitable neo-classic west frontispiece, yet at the same time, curiously enough, the two westernmost bays were constructed in perfect imitation of Apogec Gothic. It remains an open question whether the same Renaissance century made the apse chapels after a fire in 1668. Some say they are of the XIV century, that the choir, as first built, had no ambulatory, but that one was added soon after, with radial chapels. There is a noble purity in Châlons Cathedral, due in large part to its soaring monolithic piers. No church is richer in tombstones, and its stained glass is plenteous. In the eastern clearstory are three lovely silver and blue XIII-century windows; the north rose of the transept is early XIV century and the first window in the nave's south aisle is another good example of that period. The same aisle shows a brilliant XV-century light, ruby red in effect, and a window of 1509, wherein the Blessed Virgin's life is explained by quaint inscriptions. Some XII-century glass from Châlons Cathedral is in the Trocadéro Museum at Paris. Just as Champagne had proved herself a pioneer in the first days of the national art, so she distinguished herself in later times when Rayonnant Gothic turned to Flamboyant art. Among the few churches built during the transition between those two phases is the cathedral-like Notre-Dame-de-l'Épine, in the fields a few miles from Châlons-sur-Marne, a link connecting St. Urbain at Troyes with the goodly array of Flamboyant buildings that sprang up in the ancient capital of Champagne. The interior proportions of Notre-Dame-de-l'Épine resemble those of Rheims Cathedral, and its rood screen recalls the _jubé_ of the Madeleine church at Troyes.