This is a study and translation of the section on pericarditis in Al Taisir book written by the Muslim physician Ibn Zuhr (Avenzoar) who lived and practiced in Eshbeelia (nowadays Seville, Andalusia, Spain) between 1091-1162 AD. Ibn Zuhr described the serous type of pericarditis as well as the pathological findings in fibrinous pericarditis. His description of the latter may also fit with the picture of chronic fibrous pericarditis. He also described acute purulent pericarditis and...