Adolf I was King of Germany for half a dozen years at the end of the 13th Century.

He was born in 1255. His father was Walarm II, the Count of Nassau, and his mother was Adelheid of Katzenelnbogen. Nassau at that time was a relatively new county, dominated by Nassau Castle and containing the Bishopric of Worms.

In 1270, Adolf married Imagina of Isenburg-Limburg. They had eight children, five of whom lived into adulthood: Robert, Gerlach, Walram, Adelheid, and Matilda.

Adolf's father died a few years later, and Adolf inherited the title of Count of Nassau. One of many powerful nobles at this time, Adolf improved his stature when he gained the favor of King Rudolf I. As had been the case with several of his predecessors, the king was engaged in a struggle for supremacy, seeing off his main rival in 1282 but not having enough support to have his son crowned and a succession ensured before he died.

The nobles gathered in 1291, after Rudolf's death, to choose a new leader. Adolf was one of a handful of powerful candidates, but none of his rivals or indeed his supporters was willing to back him without getting something in return. Adolf made many promises and got enough votes to be elected king. Nominally, he would have had to keep most of the promises that he made in order to hold on to power. He proved able to break such agreements in order to secure more powerful allies. One of the most prominent of those was England's King Edward I, who recruited Adolf for a war against France. That war never materialized because Pope Boniface VIII threatened excommunication for anyone who started it, but Adolf soon found himself deeply involved in another conflict, in Thuringia. His actions there angered enough of the German nobles that he eventually lost any hope of maintaining his authority. He was officially deposed on June 12, 1298. The nobles then selected Rudolf's son, Albert, as the new king.

Adolf refused to accept his deposition, and he definitely refused to recognize Albert as the new king. Adolf took up arms and recruited an army; Albert did as well; and the two sides came to blows at the Battle of Göllheim, on July 2, 1298. Adolf died on the battlefield, and his army then fled, leaving Albert to take over.