Müller, Johann Known as Re·gi·o·mon·ta·nus 
(rē′jē-ō-mŏn-tānəs, -tä-, rĕj′ē-) 1436-1476.
(rē′jē-ō-mŏn-tānəs, -tä-, rĕj′ē-) 1436-1476. German mathematician and astronomer who established the study of algebra and trigonometry in Germany and contributed to the revival of astronomy during the Renaissance.