military · 338 · Nisibis
Shapur II dammed the Mygdonius and let it go against the walls, which came down — and then, the accounts say, the flood bogged his own cavalry and elephants in the mud while the breach was rebuilt overnight. Theodoret and Ephrem, who was in the city, both credit the bishop: Jacob went up on the wall and prayed, and a plague of gnats and mosquitoes maddened the horses and the elephants. Ephrem is a contemporary and Theodoret is a century later, and both had every reason to tell it as a miracle, which is why this is marked traditional rather than historical. The siege itself is not in doubt and neither is the outcome. Jacob is one of the bishops who signed at Nicaea, he is said to have taught Ephrem, and the city kept him as its patron until it was handed to Persia in 363 — at which point, as the seed two rows above this one records, the Christians walked out and took the tradition with them.
To take the strongest Roman fortress on the Persian frontier, which Shapur besieged three times and never held.
The city held; the bishop died the same year; and the siege became the founding story of the Nisibene church.