The original royal chapel inside the Palazzo Reale (Royal Palace) in Palermo was built in the late 11th century. The Palatine Chapel - Cappella Palatina in Italian - was built on top of it in the early part of the 12th century, making the old chapel a crypt. Mosaic art was at its peak when the chapel was constructed, and the chapel’s interior is covered in gorgeous mosaics. Many surfaces are predominantly gold, which makes the entire chapel appear to glow.
The mosaics in the Palatine Chapel date from the 1140s, just after the chapel was built, through the 1170s. The older mosaics are the best examples of Byzantine art in the chapel, although you’ll see even more mosaics of this quality if you visit the Monreale Cathedral in the hills outside Palermo.