Jacques Feldbau was a French mathematician, born on 22 October 1914 in Strasbourg, of an Alsatian Jewish traditionalist family.

[1] In a paper, written together with Ehresmann, he introduced the notion of an associated bundle and proved results known today as the exact homotopy sequence of a fibration.

[2] Described by Michèle Audin as "a handsome young man with a very friendly and likeable personality"[citation needed] he demonstrated an early interest in mathematics, whilst also being enthusiastic about music and sport.

Demobilized after the armistice of 22 June 1940, he was appointed associate professor at the School of Chateauroux, but was forbidden to teach by the laws of exclusions of 3 October 1940 on the status of Jews, promulgated by the Vichy regime under the Pétain government.

In order to earn a living he gave mathematics lessons and continued his research in topology for his doctoral thesis; he also became a member of the Resistance movement.

The status of Jews was one of the additional burdens of Nazi occupation; it quickly became impossible for a scientist labelled as "non- Aryan " to publish under his name.

Despite his somewhat clumsy methods (hardly surprising in a beginner) he came up with some interesting results...On the night of 24 to 25 June 1943 the "roundup of Gallia" took place whereby 38 Strasbourg university students were arrested in the Gallia university foyer in retaliation for three attacks against the Germans, following the execution on 24 June of two members of the Gestapo in the house of a resistance member, Professor Jean-Michel Flandin.

Amongst its key findings, we note the following fundamental theorem: "a fiber space of a simplex is trivializable "and its corollary, "to give a bundle on a sphere

These results are so obvious now among the specialists in algebraic topology that their origin is somewhat forgotten, writes André Weil, in the comments of his collected works.

A note to the Proceedings of the Academy of Sciences, co-authored with Charles Ehresmann, outlines what was later called the homotopy exact sequence of fiber bundles.