Florian Cajori (1859‒1930) was an eminent Swiss-American mathematician who wrote several books on the history of Mathematics. He is considered the founding father of the History of Mathematics as an academic discipline.
Indeed he was the first to be appointed as professor in History of Mathematics at the University of Berkeley, California, which was the first chair on this subject created in the United States. He held the chair in Berkeley until his death and is still one of the most cited and quoted historians of mathematics of all time.
His History of Mathematical Notations has been described as “unsurpassed”.