The
Heidelberg Catechism (1563), one of the
Three Forms of Unity, is a
Protestant confessional document taking the form of a series of questions and answers, for use in teaching
Reformed Christian doctrine. It was written in 1563 in
Heidelberg, present-day
Germany. Its original title translates to
Catechism, or Christian Instruction, according to the Usages of the Churches and Schools of the Electoral Palatinate. Commissioned by the
prince-elector of the
Electoral Palatinate, it is sometimes referred to as the "Palatinate Catechism." It has been translated into many languages and is regarded as one of the most influential of the Reformed
catechisms.