territory of Islam temporarily pacified, Muawiyah's extra- ordinary energies sought new outlets in military campaigns by land and sea, thus resuming the course of Moslem expansion which had been interrupted by the two civil wars.
Eastward these campaigns resulted in completing the subjugation of Khurasan (663-671), crossing the Oxus and raiding Bukhara in Turkestan (674). Merv, Balkh, Herat and other cities which were to develop into brilliant centres of Islamic culture were captured. The army returned to Iraq laden with booty from the Turkish tribes of Trans- oxiana. They thus established the first contact between Arabs and Turks, destined to play a major role in later Islamic affairs.
To the west the city of Kairawan was established in Tunisia as a base for military operations against the Berbers. It was built partly with material taken from the ruins of Carthage. As the Berbers were Islamized, they were pressed into the Arab army and utilized in chasing the Byzantines out of Algeria. Brilliant as it was, this campaign, like that in Central Asia, was of no lasting significance, because it was not followed up by occupation. Here, as in Transoxiana, the work had to be done over again.
During the Umayyad period, as in the early Abbasid, the frontier between Arab and Byzantine lands was formed by the great ranges of the Taurus and Anti-Taurus. As the two hostile states stood face to face across this line, they first sought to keep each other off by turning the intervening stretch of land into a desolate terrain. Muawiyah con- tributed to the creation of this unclaimed waste zone. Later Umayyads pursued a different policy, aiming at establishing a footing there by rebuilding as fortresses abandoned or destroyed towns and building new ones. Thus grew a cordon of Moslem fortifications stretching from Tarsus in Cilicia to Malatya on the upper Euphrates. These fortresses were strategically situated at the inter- sections of military roads or the entrances of narrow passes.
