Ammianus Marcellinus (born in Antioch, c. 330 AD) was a soldier and historian. In 378 AD he went to Rome. He was a friend of Symmachus, the leading literary figure in the city. His History (Res Gestae) is a continuation of the Histories of Tacitus. Only the last eighteen books have survived, starting with the year 353.

Res Gestae XIX,10,4
(in 359 AD Tertullus, city prefect, when storms prevented the grain ships entering harbour and there was serious danger of riots in Rome, left hurriedly for the coast)
Dum Tertullus apud Ostia in aede sacrificat Castorum, tranquillitas mare mollivit, mutatoque in austrum placidum vento, velificatione plena portum naves ingressae frumentis horrea referserunt. While Tertullus sacrificed at Ostia in the temple of the Castors, the wind dropped and the sea was calmed; then the wind changed to a gentle breeze from the south and the ships in full sail entered the harbour and filled the granaries with corn.

Translation: R. Meiggs, p. 345.