Steppenwolf was the general of the Parademon Army of Apokolips. Although not nearly as powerful, Steppenwolf was a much more tactical and smart being than Darkseid. It was due to this that unlike most New Gods, he was not fully loyal to Darkseid.
Steppenwolf led his Parademons into many different planets, destroying each in an attempt to find the daughter of his king and leader Darkseid. Upon arriving on Earth, Steppenwolf, although in charge, played a background role in disarming Earth's defenses. This mainly meant that he was to neutralize Earth's heroes while Darkseid was in battle with them. Although he took out their main hero, Superman, and with Desaad began to convert him to be an Apokoliptan soldier, he was thwarted and effectively taken out from the battle by Batman.
On Earth-2, Steppenwolf's fight against the Batman, Superman and Wonder Woman of that world lasted years. Although the Trinity was defeated and "killed" in the end, the Batman ended up destroying the Boom Tube system, thus forcing Steppenwolf to be stuck on Earth-2. With Superman successfully becoming the seemingly loyal soldier Bruutal and Wonder Woman's daughter Fury under his fist, Steppenwolf spent five years hiding from the World Army and formulating to take over Earth 2. Eventually, Steppenwolf recruited Bedlam and the Beguiler to his goal and after taking over Dherain, began to fight the World Army over possession of Earth 2. However, moments after completing his goal and defeating the World Army, Steppenwolf was killed by Brutaal.