There was one class of decurions which seems to have caused the Emperors considerable perplexity. It was those who, whether from a genuine religious motive or in order to shirk the municipal burdens, took orders in the Christian Church. A pagan Emperor like Julian had no scruple in recalling them sternly to their civil duties, but Christian Emperors found it difficult to assert such a principle. They had to sustain the curial system at all costs, and yet avoid giving offence to the Church. Theodosius the Great laid down that the estates of decurions who had become presbyters or deacons before a certain year should be exempt from municipal obligations, but that those who had taken orders after that year should forfeit their lands to the State. He qualified this law, however, by a later enactment, which provided that if the presbyter or deacon had a son who was not in orders, the son might keep the paternal property and perform the accompanying duties. Now Calpurnius belonged to this class of decurions who had sought ordination. He was a Christian deacon, and his father before him had been a Christian presbyter. And it would seem as if they had found it feasible to combine their spiritual with their worldly duties. In any case, we may assume that the property remained in the family; it was not forfeited to the State. [Sidenote: INVASIONS OF BRITAIN] Whether the burdens laid upon them from Milan or Constantinople were heavy or light, Calpurnius and his fellows in the northern island were keenly conscious that the rule of their Roman lords had its compensations. For Britain was beset by three bold and ruthless foes.[23] The northern frontier of the province was ever threatened by the Picts of Caledonia. Her western shores dreaded the descents of the Gaels and Scots of Ireland, while the south and east were exposed to those Saxon freebooters who were ultimately to conquer the island. Against these enemies, ever watching for a favourable opportunity to spoil their rich neighbour, the Roman garrison was usually a strong and sure protection for the peaceful Britons. But favourable opportunities sometimes came. Potitus, at least, if not Calpurnius, must have shared in the agonies which Britain felt in those two terrible years when she was attacked on all sides, by Pict, by Scot, and by Saxon, when Theodosius, the great Emperor’s father, had to come in haste and put forth all his strength to deliver the province from the barbarians. In the valley of the Severn the foes whom men had to dread now were Irish freebooters, and we need not doubt that in those years their pirate crafts sailed up the river and brought death and ruin to many. Theodosius defeated Saxon, Pict, and Scot, and it would seem that he pursued the Scots across the sea, driving them back to their own shores. The Court poet of his grandson sings how icebound Hiverne wept for the heaps of her slain children. After this, the land had peace for a space.