Under Basil I the Macedonian (r. 867–886) Byzantine troops recaptured Cyprus, which was established as a theme, but after seven years the island reverted to the previous status quo. Once again, in 911, the Cypriots helped a Byzantine fleet under admiral Himerios, and in retaliation the Arabs under Damian of Tarsus ravaged the island for four months and carried off many captives. The isolation of Cyprus from the rest of the Greek-speaking world assisted the formation of a separate Cypriot dialect. This period of Arab influence lasted until the 10th century.