Cauchy-Goursat Theorem/Historical Note

Historical Note on Cauchy-Goursat Theorem
The Cauchy-Goursat Theorem was actually first investigated and proved by, but it was just one of the things that he failed to get round to publishing.

He stated it in a letter of $1811$ to his friend, where he says:
 * This is a very beautiful theorem whose fairly simple proof I will give on a suitable occasion. It is connected with other beautiful truths which are concerned with series expansions.

was, however, the first to publish a proof.

independently discovered this theorem during his exercise to rebuild the theory of complex analysis from first principles.