He taught at Königsberg University and was the first Prussian scholar to hold a teaching chair in Art history and Aesthetics.

[1][2] Ernst August Hagen was born in Königsberg, at that time the administrative capital of East Prussia (and for almost a decade after 1806 when the king fled from Berlin, the home of the Prussian Court).

Ernst August's older brother, Carl Heinrich Hagen (1785-1856) was a professor of law and economics and a senior government official who had become became an early and prominent advocate of free trade after studying the work of Adam Smith.

[4] Hagen passed his Abitur (school final exams) at the Altstadt Gymnasium which opened the way to his study of natural sciences and medicine in 1816 at the city's "Albertina University".

He subsequently visited the principal artistic centres in Germany and Italy, making the acquaintance of a number of high-profile figures in arts and scholarship, forming friendships that were both "professional" and "personal".

[1] By the time he got back to Königsberg, in 1824, his burgeoning network included Carl Friedrich Gauß, Johann Wolfgang von Goethe, Jean Paul and Bertel Thorwaldsen.

He argued powerfully for the new Königsberg Arts Academy which opened in 1845, using personal contacts as appropriate, and in the end it was the new king himself, with whom Hagen had studied at the court apothecary back in 1807/08, who signed the cabinet order approving the project in May 1842.

He was himself raised to the nobility (thereby becoming identified in subsequent sources as Ernst Heinrich von Hagen) in 1871 and between 1876 and 1882 served as commander of the Number 5 Dragoon Regiment.