Galois and his groups (Q664620)

In the abstract of his paper, the author writes ``\dots This article, which has been written to celebrate the 200th anniversary of his birth, focuses on a study of his relationship with his groups: how Galois defined them; how he used them; what he knows about them; and his inventiveness\dots'' He starts with a chronology of Galois life and with a short account of his mathematical achievements. Then he describes how Galois invented groups by considering permutations of the roots of a polynomial equation and gives a detailed discussion of Galois' investigations of groups and of how Galois used groups in various context. Finally, the author comments on the ``Originality in the ideas of Galois''.