Medievalist and American architectural historian. Egbert was born to Rev. George Drew Egbert (1865-1940) and Kate Estelle Powers (Egbert) (d. 1938); his father was a Congregational minister and collector of early American furniture. The younger Egbert received his B.A. from Princeton University in 1924. He studied architecture, receiving an M.F.A. in 1927. Egbert continued graduate between 1927-1929 under Charles Rufus Morey, who was at that time engaged in cataloging the collection of the Museo Cristiano, part of the Vatican library.

Renaissance-subject art historian and appraiser; part of the greater Richter family of art historians. Richter was the son of Clemens Max Richter, M.D. (1848–1936), a surgeon and Emma Sophia Bierwirth (Richter) (1853-1929), both German immigrants. His older cousin was Jean-Paul Richter, a Leonardo scholar in Germany. The younger Richter began college at the University of California, Berkeley with the intent of following in his father’s footsteps studying science. With his parents’ divorce, he accompanied his mother in returning to Dresden, Germany in 1896.

Philanthropist and benefactor of the arts; nephew of art historian Aby M. Warburg; briefly taught art history at Bryn Mawr. Warburg was the youngest of five children of philanthropist Felix Warbug (1871-1937), a partner in the investment firm of Kuhn, Loeb & Company and brother of the German art historian Aby M. Warburg. His mother was Frieda Schiff (Warburg) (1876-1958), the only daughter of merchant banker and financier Jacob H. Schiff (1847-1920).