约翰尼斯·德·萨克罗博斯科Johannes de Sacrobosco

德·萨克罗博斯科或约翰尼斯·德·萨克罗博斯科在牛津接受教育。他成为尼思斯代尔德·萨克罗博斯科修道院圣奥古斯丁修会的教士。

1220年，德·萨克罗博斯科前往巴黎学习。尽管关于德·萨克罗博斯科的几乎所有日期都是猜测，但我们确实确切知道一个日期，因为1221年6月5日，他被任命为巴黎大学的教师。此后不久，他成为巴黎的数学教授。

德·萨克罗博斯科在他的教学中推广了阿拉伯的算术和代数方法。在De Algorismo中，他讨论了正整数的计算。该书包含11章，每章分别讨论加法、减法、乘法、除法、平方根和立方根等主题。

1220年，德·萨克罗博斯科写了Tractatus de Sphaera，一本分为四章的天文学书籍。第一章讨论地球在球形宇宙中的形状和位置。第二章讨论天空中的各种圆。第三章描述从不同地理位置看天体的升落，而第四章简要介绍了克劳狄乌斯·托勒密的行星和食理论。

这本书早于罗伯特·格罗斯泰斯特的天文学书，写得很好，从13世纪中叶起在整个欧洲被广泛使用。克里斯托佛·克拉乌在16世纪使用过它，直到17世纪它仍然是基础天文学教材。它基本上是1472年印刷的第一本天文学教材。尽管作为教学书籍寿命很长，弗朗切斯科·巴罗齐早在1570年就指出了书中的84处错误。

德·萨克罗博斯科于1232年写了De Anni Ratione。这本书涉及时间，研究日、周、月、年以及月亮和教会历法。他坚持认为儒略历有10天的误差，应当予以纠正。他建议通过每288年省略一天来实现历法改革。

他还写了若干其他书，包括关于象限仪的Tractatus de Quadrante。

John of Holywood or Johannes de Sacrobosco was educated at Oxford. He became a canon of the Order of St Augustine at the monastery of Holywood in Nithsdale.

In 1220 Sacrobosco went to study in Paris. Although almost all dates for Sacrobosco are guesses we do know one date precisely for, on 5 June 1221, he was appointed a teacher at the University of Paris. Soon after this he became professor of mathematics at Paris.

Sacrobosco promoted Arabic methods of arithmetic and algebra in his teachings. In De Algorismo he discusses calculating with positive integers. The work contains 11 chapters, one each on topics such as addition, subtraction, multiplication, division, square roots and cube roots.

In 1220 Sacrobosco wrote Tractatus de Sphaera a book on astronomy in four chapters. The first chapter deals with the shape and place of the Earth within a spherical universe. The second chapter deals with various circles on the sky. The third chapter describes rising and setting of heavenly bodies from different geographical locations while the fourth chapter gives a brief introduction to Ptolemy's theory of the planets and of eclipses.

The book, which predates Grosseteste's astronomy book, is well written and was widely used throughout Europe from the middle of the 13th Century. Clavius used in the 16th Century and it was still the basic astronomy text until the 17th Century. It was essentially the first astronomy text to be printed in 1472. Despite its long life as a teaching book Barocius had pointed out 84 errors in the book as early as 1570.

Sacrobosco wrote De Anni Ratione in 1232. This book deals with time, studying the day, week, month, year as well as the Moon and the ecclesiastical calendar. He maintains that the Julian calendar is 10 days in error and should be corrected. He suggest a reform of the calendar achieved by omitting one day every 288 years.

He wrote a number of other book including Tractatus de Quadrante on the quadrant.