According to Strabo and Arrian, Alexander ordered the island named after the Aegean Icaria because it resembled that island in size and shape. But a more intriguing explanation has attracted scholars: the island already housed the E-kara temple, dedicated to Shamash, the Babylonian sun-god. The phonetic similarity between 'E-kara' and 'Ikaros' may have been too convenient to resist. Strengthening this connection, both Failaka in the Gulf and Icaria in the Aegean housed bull cults -- a shared religious thread linking two distant shores. Nearchos, Alexander's admiral, was likely the first Greek to explore the island. Three further expeditions followed in 324 BC, led by Archias, Androsthenes of Thasos, and Hiero, each ordered by Alexander himself to survey and inspect the island.

The ruins that remain on Failaka include something found nowhere else in the Persian Gulf: a Hellenistic fortress. The structure is roughly 60 meters on each side, semi-square in plan, with a tower at each corner. The southern main gate was secured by a large tower; the eastern gate by two. Built in the 3rd century BC, it represents the Seleucid Kingdom's grip on Gulf trade routes -- a military stronghold adapted to Hellenistic war strategies and planted on an island that controlled access to the Tigris-Euphrates river mouth. Alongside the fortress stand the remains of two Greek temples. Temple A, built in the Ionic style with fine-cut imported stone, was dedicated to Artemis.

The temple of Artemis on Ikaros came with a remarkable provision. The island's wild animals were declared sacred to the goddess, and a formal decree prohibited harming them. This was not a casual suggestion but an official act of protection, issued in an era when wildlife conservation was virtually unknown as a civic concept. The decree placed the entire island's fauna under divine guardianship. Dionysius of Alexandria, Aelian, and Ptolemy all mention the island in their writings, and Stephanus of Byzantium recorded it in his geographical encyclopedia. For ancient geographers, Ikaros was a known point on the map -- a place where Greek culture had planted itself at the edge of the known world.

Failaka sat just 15 kilometers from the mouth of the Euphrates, making it a natural checkpoint for trade flowing between Mesopotamia and the wider Gulf. After the Hellenistic period, the island became a trading post of Characene, the Parthian kingdom centered in southern Mesopotamia. Commerce continued through shifting empires. The island's position made it valuable to Sumerians, Babylonians, Persians, Greeks, and Parthians in succession -- each layer of occupation adding to the archaeological record that Danish, French, American, Italian, Polish, Georgian, Slovak, and Greek teams have been excavating since 1958. In 2025, archaeologists discovered a courtyard and building at Al-Qurainiya dating to the Hellenistic period, extending evidence of Greek presence to the island's northern reaches.