In the meantime, a second and larger sea-borne invasion had started. An enormous coalition consisting of Goths (Greuthungi and Thervingi), Gepids and Peucini, led again by the Heruli, assembled at the mouth of river Tyras (Dniester). The "Augustan History" and Zosimus claim a total number of 2,000–6,000 ships and 325,000 men. This is probably a gross exaggeration but remains indicative of the scale of the invasion. After failing to storm some towns on the coasts of the western Black Sea and the Danube (Tomi, Marcianopolis), the invaders attacked Byzantium and Chrysopolis. Part of their fleet was wrecked, either because of the Goth's inexperience in sailing through the violent currents of the Propontis or because they were defeated by the Roman navy. Then they entered the Aegean Sea and a detachment ravaged the Aegean islands as far as Crete, Rhodes and Cyprus. The fleet probably also sacked Troy and Ephesus, damaging the Temple of Artemis, though the temple was repaired and then later torn down by Christians a century later, one of the Seven Wonders of the Ancient World. While their main force had constructed siege works and was close to taking the cities of Thessalonica and Cassandreia, it retreated to the Balkan interior at the news that the emperor was advancing.