Étienne-Louis Malus (see picture) serendipitously discovered the polarization of light by reflection nearly 200 years ago. The conditions of the re-creation of his benchmark experiment are analyzed. Malus' biography is arranged around the diary he kept in Egypt as an engineer in Bonaparte's army. His experiences in war are sadly relevant. The legacies of Malus are considered, including the continued reexamination of the indispensable law that bears his name.