Complex sentence: Starting from 1135, the cathedral of Sens, dedicated to Saint Stephen, was rebuilt as one of the first Gothic cathedrals; there, in 1234 Louis IX of France celebrated his wedding to Marguerite of Provence.
Split into simpler sentences: Starting from 1135, the cathedral of Sens, dedicated to Saint Stephen, was rebuilt as one of the first Gothic cathedrals. There, in 1234, Louis IX of France celebrated his wedding to Marguerite of Provence.