In the 10th and 11th centuries the Islamic territories were the cradle of developments in the sciences. Indeed, Persian and Muslim scientists built an effective structure in all sciences based on what their ancestors had earlier gained. In the following two centuries this legacy of advanced scientific knowledge reached the West, and in due course made the foundation of the late Medieval and Renaissance Western developments. The Islamic scholars, therefore, were the pioneers of early modern developments in mathematics and the other sciences. Abu-Rayhan al-Biruni was regarded as the finest mathematician, astronomer and scientist of his age. In 1029, Biruni wrote Al-Tafhim in Persian for a Persianspeaking student girl, Rayhanah. Later, he rewrote the book in Arabic.
Al-Tafhim starts with a general survey of mathematics (geometry and arithmetic), and proceeds to astronomy and the calendar, with a discourse on the use of the astrolabe. It then goes on to discuss astrology in great detail, involving a great deal of astronomical observation and measurements. Al-Tafhim was designed as a teaching text, and is divided into 530 questions and answers in 492 pages. The book has been regarded by Western scholars as the greatest scientific encyclopedia of its age, and its author is taken to be one of the greatest, most inventive and most enquiring of scientific thinkers. It has been translated into English, Italian, German and Russian. The text of Al-Tafhim, inscribed on the International Memory of the World Register in 2011, is the oldest surviving copy in Persian language transcribed in 1143.