El Greco was a man who lived a long, long time ago in a place called Greece. He was actually born with a different name, but when he moved to Spain, people started calling him "El Greco" which means "The Greek."
Now, El Greco was very good at painting. He painted pictures of people and things that were very important to him. He liked using bright colors, and he also liked making things look a little bit strange or different than they really were in real life.
One thing that made El Greco's paintings different from others was that he liked to make his people really tall and skinny. This is called "mannerism." He would also make the people and things in his paintings look like they were really far away, even if they were right up close in the picture.
Some people really liked El Greco's paintings, and they even gave him lots of money to make more of them. Others thought his paintings were too weird and didn't like them very much.
But even though some people didn't like his paintings at first, over time more and more people started to appreciate El Greco's unique style. Today, lots of people think El Greco was one of the greatest painters of all time, and his paintings can be found in museums all around the world.