Okay kiddo, so a long time ago, in a place called the Roman Empire, there were these people called Christians. They believed in a man named Jesus Christ who said that people should love one another and help those in need.
Now, the rulers of the Roman Empire didn't like these Christians because they thought they were weird and didn't follow the rules of the Roman religion. So, they started making laws that said Christians had to worship the Roman gods or else they would be punished.
These punishments were really bad, like getting thrown to wild animals, set on fire, or getting killed in front of other people. Many Christians were scared, and some even decided to hide or pretend they weren't Christians so they wouldn't be punished.
But, some Christians were really brave and refused to give up their beliefs, no matter what the Romans did to them. They even wrote letters to each other and encouraged each other to stay strong and faithful to their beliefs.
In the end, the Roman Empire changed and stopped persecuting Christians. They became more accepting of their religion and eventually, Christianity became the dominant religion of the Roman Empire.
So, that's what happened during the persecution of Christians in the Roman Empire. It was a sad time for many, but it also showed that people can be really brave and stand up for what they believe in, even when it's hard.