Celtic warfare was the way that the people who lived in parts of Europe fought a long, long time ago. They were called the Celts, and they had their own special weapons and ways of fighting that made them really tough and intimidating in battle.
One of the main weapons that the Celts used was the sword. It was a long metal blade that was sharp enough to cut through things like armor and shields. They also used something called a spear, which was a long stick with a pointy metal tip on the end. The Celts could throw their spears or use them to poke at their enemies from far away.
Celtic warriors also wore special clothes to protect themselves in battle. They wore a helmet on their head to cover their face, and they had armor made of metal that was strong enough to stop arrows and other sharp things from hurting them. They also had shields that they could hide behind to protect themselves from getting hit.
In battle, the Celts would stand in lines with all of their friends, and they would charge forward to meet their enemies. They would use their swords and spears to try to poke and strike their enemies, and they would use their shields to block attacks coming at them.
Celtic warfare was very different from the way that people fight today, but it helped the Celts survive and conquer many lands in Europe long, long ago.