Complex sentence: The massive bronze Gniezno Doors of Gniezno Cathedral, of about 1175, are decorated with 18 reliefs of scenes from the saint's life, the only Romanesque church doors in Europe to contain a cycle illustrating the life of a saint.
Split into simpler sentences: The massive bronze doors of Gniezno Cathedral, from circa 1175, are decorated with eighteen reliefs of scenes from the Saint's life. They are the only Romanesque ecclesiastical doors in Europe depicting a cycle illustrating the life of a saint.