The catechism was written in 1563 in the city of Heidelberg,
the capital city of the Palatinate. This German state had for some
time been troubled by the conflicts between the Lutherans and the
Calvinists. However when the God fearing Frederick III came to the
throne, who not only sought the political welfare of his country,
but especially sought to maintain the pure religion as the
foundation for the true welfare of his people, Zacharias Ursinus and
Caspar Olevianus were instructed to draw up a catechism which could
be used for instruction in schools and in churches. The elector
himself wrote the preface for this book. It was like a thunderclap
from heaven when the Heidelberg catechism appeared in January, 1563.
Translated into all European languages, it was distributed in all
countries. Rome trembled upon its foundations, the Lutherans were
furious. All those who reviled the pure doctrine worked together to
make the hated catechism disappear. The elector himself was summoned
before the Diet of Augsburg in 1566, and he went, although loss of
his estate and even death threatened him. He defended with much
liberty the true doctrine confessed in the catechism, and the Lord
gave him so much influence that his enemies were silenced, and he
was permitted to use this instruction in the Christian doctrine
throughout his domain. Thus the truth triumphed.
From Heidelberg the catechism was introduced into the
Netherlands through the services of the faithful, zealous chaplain
of Frederick III, Peter Datheen. The provincial Synod in 1574
decided to use this catechism, and in 1578 the General Synod did
likewise, and the churches of the Netherlands have never been sorry.
This book has been reprinted innumerable times. Many explanations of
the catechism have been published, and up to this present day those
who love the truth of God, love to hear catechism preaching.
The Heidelberg Catechism was composed in Heidelberg at the request of Elector Frederick III, who ruled the Palatinate, an influential German province, from 1559 to 1576. An old tradition credits Zacharius Ursinus and Caspar Olevianus with being coauthors of the new catechism. Both were certainly involved in its composition, although one of them may have had primary responsibility. All we know for sure is reported by the Elector in his preface of January 19, 1563. It was, he writes, "with the advice and cooperation of our entire theological faculty in this place, and of all superintendents and distinguished servants of the church" that he secured the preparation of the Heidelberg Catechism. The catechism was approved by a synod in Heidelberg in January 1563. A second and third German edition, each with small additions, as well as a Latin translation were published the same year in Heidelberg. Soon the catechism was divided into fifty-two sections so that one Lord's Day could be explained in preaching each Sunday of the year.
The Synod of Dort in 1618-1619 approved the Heidelberg Catechism, and it soon became the most ecumenical of the Reformed catechisms and confessions. The catechism has been translated into many European, Asian, and African languages and is the most widely used and most warmly praised catechism of the Reformation period.

Sporen uit de tijd van de Reformatie (IV), door G. Roos, Reformatorisch Dagblad 23-10-1979
Kersten, Heidelberg Catechism, Vol.1. part 2
Christian Reformed Church, Heidelberg Catechism