An expedition which he sent out to the East, professedly with this object, in the year A.D.267, failed utterly, its commander, Heraclianus, being completely defeated by Zenobia, the widow and successor of Odenathus.

Odenathus himself was murdered by a kinsman three or four years after his great successes; and, though Zenobia ruled his kingdom almost with a man's vigor, the removal of his powerful adversary must have been felt as a relief by the Persian monarch.

It is evident, too, that from the time of the accession of Zenobia, the relations between Rome and Palmyra had become unfriendly; the old empire grew jealous of the new kingdom which had sprung up upon its borders; and the effect of this jealousy, while it lasted, was to secure Persia from any attack on the part of either.
It appears that Sapor, relieved from any further necessity of defending his empire in arms, employed the remaining years of his life in the construction of great works, and especially in the erection and ornamentation of a new capital.

The ruins of Shahpur, which still exist near Kazerun, in the province of Fars, commemorate the name, and afford some indication of the grandeur, of the second Persian monarch.

Besides remains of buildings, they comprise a number of bas-reliefs and rock inscriptions, some of which were beyond a doubt set up by Sapor I.
In one of the most remarkable the Persian monarch is represented on horseback, wearing the crown usual upon his coins, and holding by the hand a tunicked figure, probably Miriades, whom he is presenting to the captured Romans as their sovereign.