He maintained a long and close friendship with Arthur Rimbaud whom he first met in April 1865 when they attended school together in Charleville in the Ardennes region of France.
He was one of the few (seven) recipients of the privately printed A Season in Hell,[3] though Rimbaud later asked for it back to give it to someone else.
[6] Through Rimbaud, Delahaye also met poet Paul Verlaine and became friendly with him.
Verlaine wrote a poem - Sonnet Boiteux - which is dedicated to him.
Delahaye mixed his civil service career, working at the Education Ministry,[7] with writing biographical material on both Rimbaud and Verlaine, contributing first-hand accounts of the poets' lives and families.