  Today, February 11, is the International Day of Women and Girls in Science,
the perfect day to remember Mileva Mari\'{c} Einstein, a brilliant but largely
unknown scientist. While her husband, Albert Einstein is celebrated as perhaps
the best physicist of the century, one question about his career remains: How
much did his first wife contribute to his groundbreaking science? While it is
not possible to credit her with any specific part of his work, their letters
and numerous testimonies presented in books dedicated to her $^{[1-5]}$ provide
substantial evidence on how they collaborated from the time they met in 1896 up
to their separation in 1914. They depict a couple united by a shared passion
for physics, music and for each other. So here is her story.
