Long, long ago, there were two big groups of people in Europe - the Croatians and the Ottomans. They lived in different places and spoke different languages.
Like some kids when they play together, they sometimes got into fights. Only these fights were even bigger and lasted for a really long time - 100 years to be exact!
Now, the Croatians and the Ottomans didn't agree on a lot of things. One of the main reasons they kept fighting was because they both wanted control over certain lands. They thought the land was important for different reasons, such as for farming, trade, and having a strong army.
The Croatians and the Ottomans would send their soldiers to fight in battles with each other. They both had different weapons and strategies for fighting.
Sometimes the Croatians would win and sometimes the Ottomans would win, but neither side could defeat the other once and for all. So they just kept fighting, and fighting for 100 years!
Eventually, after many years of fighting, the two sides signed a peace treaty. This was an agreement that they wouldn't fight anymore and that they would try to get along better.
Although the fighting was over, this war had lasting effects on the countries and the people involved. It taught them that it's important to try and solve disagreements without violence and to always try and find peaceful solutions.