This is a short introduction to the Ostrih Bible (perhaps better known as the Ostrog Bible), the first printed Bible in Old Church Slavonic. It was published in 1581 in the Ukrainian town of Ostroh, at the time controlled by the Polish-Lithuanian Commonwealth. (There seems to be some confusion over how the name of the town should be transliterated into English!) The printer, Ivan Fyodorov, was a Russian expatriate, while the patron of the project was a Ukrainian aristocrat, Prince Konstantin Ostrogski. Curiously, the staunchly Orthodox Ostrih Bible has both Orthodox and Catholic traits. The author of this article, Robert Mathiesen, points out that Konstantin Ostrogski considered Protestants and Socinians to be the most dangerous opponents of Orthodoxy at the time, the serious Catholic-Orthodox conflict still being about two decades into the future. The Ostrih Bible has played an important cultural and religious function in many Slav lands, and Mathiesen´s article was originally a lecture delivered at a pro-Ukrainian exhibition in the United States, which explains why most names are given in Ukrainian transliteration. Apparently, one of the original copies was shown at the exhibition, held at the Houghton Library at Harvard.