We understandably think of the Heidelberg Catechism (1563) as a German-language catechism. Its first translation, however, was into Latin as the Catechesis Palatinae. This was important because, when the catechism was published relatively few people in the world spoke or read German. In the 16th and 17th centuries, Latin was the universal language as English is today. Even in the schools of the time the catechism was taught in Latin. The Synod of Dort adopted a Latin edition of the catechism in 1619. In other words, until the 18th and 19th centuries, most who read the catechism probably read it in Latin.
David Noe has a wonderful YouTube site, Latin Per Diem in which he walks us through various Christian Latin texts for about 4 minutes each day. He has just started a series through Heidelberg 1. If you’re interested in the catechism or in Christian Latin David is “doing work” as they say on sports-talk radio. You should also see his wonderful translation of Franciscus’ Junius, A Treatise On True Theology.