In the 1650s, historic Christianity in England was challenged
by Socinianism. This heretical system was to a large extent based on
Arianism, which had plagued the ancient church. Owen wrote his Vindiciæ
Evangelicæ after being commissioned by the Council of State to refute
Socinianism. In it he deals with the writings of John Biddle, ‘the father
of English Socinianism,’ Hugo Grotius, the famous Dutch statesman and
philosopher (who was not an avowed Socinian) and the Racovian Catechism,
which was associated with Socinus himself.