Ferdinand IV was King of Germany for a time in the mid-17th Century. He was the oldest son of the famous Ferdinand III, whose imperial reign coincided with the end of the Thirty Years War.

He was born on Sept. 8, 1633, in Vienna. His father was the future Holy Roman Emperor Ferdinand III, and his mother was Maria Anna of Spain. The elder Ferdinand was very much in mind of succession and wanted his oldest son to be accepted as the next ruler of the Holy Roman Empire, Germany, and various other kingdoms. The boy was crowned King of Bohemia in 1646, when he was 13, and King of Hungary the following year.

The Thirty Years War was winding down by this time, as negotiators for both sides were meeting on and off for a handful of years. The war ended for most of the participants with the Peace of Westphalia, in 1648. Ferdinand III threw in his lot with Spain in its continued fight with France but otherwise tried to keep the peace within the Holy Roman Empire itself. The German states set about rebuilding, after three decades of warfare (political and religious) that torn them apart.

Ferdinand III, who had become Holy Roman Emperor in 1637, secured for his oldest son the German throne in 1653. He was crowned as such in Ratisbon on June 18 of that year. By this time, young Ferdinand was 20. His father had high hopes for him and arranged for him a marriage, to Maria Theresa, daughter of Spain's King Philip IV. Before that marriage could take place, young Ferdinand died, of smallpox, on July 9, 1654. His younger brother Leopold succeeded him as first King of the Romans (Germany) and then Holy Roman Emperor.