Why Did Europe Stop Counting Years from the Birth of Christ?

Long ago, people didn't count years starting from Jesus' birthday. They counted things like 'in the year Caesar ruled' or 'when the general won the war.' This was confusing because different places had their own lists! Then, a monk named Dionysius looked at old records and said, 'Jesus was born in 1 AD!' Most people liked this idea so much that they started using it everywhere. Today, we still use his guess to know how old we are.

Dionysius didn't have a time machine. He just looked at Roman history books and counted backwards. He figured out the year Jesus was born by looking at who was king and what laws were being made. Even though he might be off by a few years, his guess was close enough for everyone to agree.

Now, when we say '2024', we know exactly how long it has been since that starting point. Without Dionysius, we might still be saying things like 'In the third year of King Henry's second reign' which is much harder to remember!