ad, named after them the Qati'a (Fief) of the Ansar.
Struck by the difficulties of every kind which had to be encountered by
poor pilgrims to Mecca from Bagdad and its neighbourhood, he ordered
Yaqtin, his freedman, to renew the milestones, to repair the old
reservoirs, and to dig wells and construct cisterns at every station of
the road where they were missing. He also had new inns built and decayed
ones repaired. Yaqtin remained inspector of the road till 767.

During the reign of Mansur the annual raids against the Byzantines had
taken place almost without intermission, but the only feat of importance
had been the conquest of Laodicea, called "the burnt" ([Greek: hae
katakekaumenae]), by Ma'yuf b. Yahya in the year 770. At first the
armies of Mahdi were not successful. The Greeks even conquered Marash
(Germanicia) and annihilated the Moslem army sent from Dabiq. In 778,
however, Hasan b. Qahtaba made a victorious raid as far as Adhruliya
(Dorylaeum); it was on his proposition that Mahdi resolved on building
the frontier town called Hadath (Adata), which became an outpost. In 779
the caliph decided on leading his army in person. He assembled his army
in the plains of Baradan north of Bagdad and began his march in the
early spring of 780, taking with him his second son Harun, and leaving
his elder son Musa as his lieutenant in Bagdad. Traversing Mesopotamia
and Syria, he entered Cilicia, and established himself on the banks of
the Jihan (Pyramus). Thence he despatched an expeditionary force,
nominally under the command of Harun, but in reality under that of his
tutor, the Barmecide Yahya b. Khalid. Harun captured the fortress Samalu
after a siege of thirty-eight days, the inhabitants surrendering on
condition that they should not be killed or separated from one another.
The caliph kept faith with them, and settled them in Bagdad, where they
built a monastery called after their native place. In consequence of
this feat, Mahdi made Harun governor of the whole western part of the
empire, including Azerbaijan and Armenia. Two years later war broke out
afresh between the Moslems and the Greeks. Leo IV., the East Roman
emperor, had recently died, leaving the crown to Constantine VI. This
prince being only ten years old, his mother Irene acted as regent and
assumed the title Augusta. By her orders an army of 90,000 men, under
the command of Michael Lachanodrakon, entered Asia Minor. The Moslems,
on their side, invaded Cilicia