On 20 June 1846, Hermes was born in Königsberg, a former German city (presently Kaliningrad, Russia). Hermes was educated at the Kneiphöfischen Gymnasium. He undertook his Abitur (final examination) at the school in 1866. After completing his secondary education, he studied mathematics from 1866 to 1870, mostly in Königsberg. His studies were interrupted due to his participation in the Franco-Prussian War between 1870 and 1871.
