[2] Hildebrandt suffered from agoraphobia,[3] which manifested itself in his choice of small auditoriums for lectures.
[4] Hildebrandt received his doctorate degree in 1898 in Berlin, with his thesis on German sculpture.
From 1908 he was a lecturer of art history, and from 1921 held the position of associate professor at the Humboldt University of Berlin.
His main research interest was in Italian Renaissance and Baroque, and he wrote several books on the topic.
He left his position in 1937 after failing to get the aryan certificate required by the rising National Socialist regime.