On two occasions Sophie changed her name so as to gain acceptance in the male-dominated world of mathematics.

Sophie found algebra fascinating. In 1798, she read an essay on number theory, and started to concentrate on this field of mathematics. When she found out that the famous mathematician Joseph Louis Lagrange was giving a series of seminars on the subject at the Ecole Polytechnique (a French academy), she contacted male friends who attended the academy and borrowed their notes and learned on her own. As she was a woman she could not attend class. At the end of the class, students had to a report to the Professor. Sophie decided to write a paper and she submitted it using a male pseudonym: M. Le Blanc. The professor was impressed with the work of M. Le Blanc, and asked to meet him. Imagine his surprise when he discovered that LeBlanc was a fictitious character, and that an 18-year-old woman who was studying maths on her own had written the paper!

Pen name

Professor Lagrange was so delighted by his discovery that he offered to mentor Sophie. When Sophie was 25, she wanted to contact Gauss, an eminent expert in the area of number theory, to communicate some of her recent findings. Realising that the Germans were highly prejudiced and uncomfortable with the idea of recognising female mathematicians, she again invoked the name LeBlanc. Gauss was so impressed with Sophie's work that the two of them began a regular correspondence. Years later, when France and Germany were at war and France invaded the German state where Gauss lived, Sophie fearing that Gauss might be taken unawares by the invasion and treated badly, she contacted a French General who was a family friend and asked him to ensure that Gauss was given protection. Gauss was surprised that he had a protector named Sophie Germain until he realised that this was none other than Monsieur LeBlanc.