Deborah was a heroine of the Jewish people during the time of Judges, around 1,100 BCE, 100 or so years after the Israelites entered the promised land of Canaan. We don’t know much about Deborah, least of all how she came to be a leader in a time when women generally had very little power. The Bible tells that she would sit beneath a palm tree to advise her people.
While Deborah was growing up, the people of Israel were dominated and harassed by the Canaanites all along their borders. Filling in the blanks a bit, we can imagine how an intelligent, determined and unusually assertive girl might be shaped to take action, if given the power. According to the story, she was given the power and she did take action. She ordered her general, Barak, to assemble an army. For some reason, Barak did not want to go into battle unless Deborah went too, so she did.
Although outnumbered, Deborah, Barak and their troops prevailed, thanks in part to heavy rains that bogged down the Canaanite chariots in mud and swamped them with flash floods. The Canaanite general Sisera was the only survivor of the battle. He took off on foot.
When Sisera came to a Bedouin camp, he asked a woman there, Yael, for some water. She gave him milk instead, which, on top of a terrible day of combat and fleeing for his life, made him drowsy. When he lay down for a nap, Yael nailed his head to the ground with a tent spike, in one temple and out the other. That was the end of Sisera and, apparently, the Canaanite threat as well.
After the victory, the people of Israel enjoyed 40 years of peace under Deborah.
Read about Deborah in Judges 4 & 5.