koechlin was born in paris, and was the youngest child of a large family. his mother's family came from alsace and he identified with that region; his maternal grandfather had been the noted philanthropist and textile manufacturer jean dollfus, and koechlin inherited his strongly developed social conscience. his father died when he was 14. though he was early interested in music his family wanted him to become an engineer. he entered the école polytechnique in 1887 but the following year was diagnosed with tuberculosis and had to spend six months recuperating in algeria. he had to repeat his first year at the école and graduated with only mediocre grades. after a struggle with his family and private lessons with charles lefebvre he entered the paris conservatoire in 1890 studying first with antoine taudou for harmony. in 1892 he started studying with massenet for composition, andré gedalge for fugue and counterpoint, and louis bourgault-ducoudray for musical history. his fellow-pupils included george enescu, ernest le grand, reynaldo hahn, max d'ollone, henri rabaud, and florent schmitt. from 1896 he was a pupil of gabriel fauré, where his fellow-pupils now included ravel and jean roger-ducasse. fauré had a major influence on koechlin; in fact koechlin wrote the first fauré biography (1927), a work which is still of value. in 1898 a grateful koechlin orchestrated the popular suite from fauré's "pelléas et mélisande" and in 1900 assisted fauré in the production of the huge open-air drama "promethée."