Complex sentence: A cross-in-square or crossed-dome plan was the dominant architectural form of middle-and late-period Byzantine churches, featuring a square centre with an internal structure shaped like a cross, topped by a dome.
Split into simpler sentences: A cross-in-square or crossed-dome plan was the dominant architectural form of middle-and late-period Byzantine churches. It featured a square centre with an internal structure shaped like a cross, topped by a dome.