Alright kiddo, have you ever seen a big round roof on a building? That's called a dome! The ancient Romans were really good at building domes. They even built the biggest dome in the world at the time, it was called the Pantheon. It was built in Rome over 2000 years ago!
The Romans used a special type of building material called concrete to make their domes. Concrete is like a mix of sand, gravel, water, and a special powder called cement. They would pour this mixture into a mold and let it dry, and then it would become a really strong dome that could hold up a lot of weight.
When the Roman Empire fell apart, a new empire took over called the Byzantine Empire. They were also really good at building domes, but they used a different kind of material called bricks. Bricks are like small blocks made of clay that are baked in an oven.
One of the most famous Byzantine domes is the one on top of the Hagia Sophia church in Istanbul, Turkey. It was built almost 1500 years ago! Like the Romans, the Byzantines made their domes really strong so they could last a really long time. They also made them look really pretty with decorations like mosaic tiles and paintings.
So, that's the story of the history of Roman and Byzantine domes. They were both really good at building them, but they used different materials and had slightly different styles. Do you have any more questions, kiddo?