Cuchulain was known as one of the greatest heroes in Irish mythology and legend. He was single-handedly the only defense for Conchobhar, the king of Ulster. Cuchulain was said to have lived in the the 1st century, B.C. Most of what was written about him and other heroes of his time weren't actually put on paper until 700 A.D. Tales about him were written down in a series of tales that was titled "Ulster Cycle."
Conchobhar was actually his uncle, and he was accepted into his court after he fought off 150 boy warriors at the age of 7. He was extraordinary as a child. He could swim very well at birth. He had seven fingers on each hand and seven toes per foot, and he even had seven pupils in each eye. His birth name was actually Setanta, but he took the name of Cuchulain because it meant "hound of Cullan." He had accidentally killed Cullan's watchdog, and offered to guard Cullan until another dog could be trained. He grew up to be well spoken and was very good with the ladies. He died tragically at the age of 27 years old. He was not even strong enough to fight at the end of his battle that took his life, so he tied himself to a pillar so he could die while still standing and fighting.
I highly recommend reading "Red Branch" by Morgan Llywelyn. This book is based on the legend of Cuchulain, and Llywelyn does an excellent job retelling the legend in a very engaging way. It recounts the story of the legendary Irish hero who defended Ulster and was powerful in battle. If you are at all interested in Irish history and legends, I would suggest novels by Llywelyn for a modern take on the old stories.