He was a commander under Hadadezer, the king of the Aramean region during David's time. He was defeated in the war against David.
2 Sam 10:16When Hadadezer saw that he had been defeated by Israel, he sent messengers and brought out the Arameans who were beyond the Euphrates, and they came to Helam, with Shobach the commander of Hadadezer's army leading them.2 Sam 10:17When David was told, he gathered all Israel together and crossed the Jordan and came to Helam. And the Arameans arrayed themselves against David and fought with him.2 Sam 10:18And the Arameans fled before Israel, and David killed seven hundred Aramean charioteers and forty thousand horsemen and struck down Shobach the commander of their army, who died there.
1 Chr 19:16When the Arameans saw that they had been defeated by Israel, they sent messengers and brought out the Arameans who were beyond the Euphrates, with Shobach the commander of Hadadezer's army leading them.1 Chr 19:17When David was told, he gathered all Israel and crossed the Jordan and came to the Arameans and arrayed his forces against them. When David arrayed his forces against the Arameans, they fought with him.1 Chr 19:18And the Arameans fled before Israel, and David killed seven thousand Aramean charioteers and forty thousand foot soldiers, and put to death Shobach the commander of the army.