Bartholomaeus Pitiscus

Bartholomaeus Pitiscus, also Barthélemy or Bartholomeo, born on 24 August 1561 and dead on 24 August 1613, was a German trigonometrist, astronomer and theologian who coined the word trigonometry. Born to poor parents at Słone near Grünberg, then part of the Duchy of Glogau in Silesia, he studied theology at Zerbst and Heidelberg, was appointed to teach the young Frederick IV, Elector Palatine, and became court chaplain at Breslau and court preacher to Frederick. He achieved fame with his Trigonometria, printed as an appendix to a work of Abraham Scultetus, which introduced the word trigonometry to English and French and consists of five books on plane and spherical trigonometry; a standalone edition with tables followed in 1608 and 1612. In his Thesaurus mathematicus of 1613 he improved the trigonometric tables of Rheticus, whose Opus palatinum de triangulis he had helped publish in 1607. He is often credited with inventing the decimal point, a claim that is disputed, and the lunar crater Pitiscus is named after him.