In the 4th century, the Arians proved to be not only a highly influential heresy, but a considerable political force within the Roman empire. The rivalry between orthodox Christians and Arians ostensibly threatened the empire’s stability. As an attempt to bring peace to the polis, the pro-Arian emperor, Valentinian II, commanded that the Church in Milan, then under Ambrose’s watch, hand over the Portian Basilica as a base of operations for the Arians.
When Ambrose, with the support of the local populace in Milan, refused the order, Valentinian, assuming the Church to be the arm of the Roman public service, one day had his troops surrounded the Church, in which Ambrose and the Christians of Milan had barricaded, in an attempt to force the Church’s being handed over to the Arians. The attempt was unsuccessful.
It is said that Ambrose was responsible for penning a line that should have as much relevance now as it did back then: The Emperor is in the Church, never above it!