174 EARLY MEDIEVAL SPAINbeen ineffective. The extension of the power of the administration
outside of Cordoba however depended more upon the play of local
politics.
The most important cities of Al-Andalus outside of the capital had
governors appointed by the amirs, and Seville in particular was often
entrusted to a member of the ruling dynasty. Away from the
Guadalquivir valley, especially in the frontier zones, such governors
were generally selected from the ranks of men with local power and
following. They were thus tribal or sectional leaders, and as their
interests and authority were locally rooted they were not always reli-
able in their allegiance to their distant overlord. They, like all office-
holders and tribal leaders, were required to take an oath of loyalty
on the accession of each new ruler.^62 The principal functions of the
governors were military, with responsibilities for public order. Whether
they, like their Visigothic predecessors, had any duties in respect of
local lands belonging to the rulers is uncertain. Perhaps, too, they
were responsible for ensuring that the latter also received their pro-
portion of any loot taken in war. Local tax collectors independently
transmitted the proceeds from taxes on non-Muslims and the tolls on
goods imported into the cities.
Precise details on financial administration are lacking, though late
accounts report that the revenue of 'Abd al-Ral)man I amounted to
300,000 silver dirherns per annum, rising by the time of 'Abd al-RaJ:nnan
III to 5,480,000.^63 The coinage of Al-Andalus consisted almost exclu-
sively of these dirherns, identical in style to those used throughout
most of the Islamic world, though with occasional fluctuations and
differences in weight, and there was no continuity with the practices
of the Visigothic period, when only small gold coins had been minted
and in very limited quantities.^64 In addition from the late seventh
century on, as the result of developments in Islamic thinking about
the sinfulness of naturalistic representation in art, a new design of
coinage had to be developed to replace earlier styles that imitated
Byzantine issues. The putting of the head of <::;hrist on their coins by
the latter in 692 may have played the major role in prompting this
stylistic revolution, that eschewed any representative design and
employed only Arabic script.^65 For economic and religious reasons a
virtually uniform coinage came to be used throughout the Muslim
world, which made no explicit reference to secular rulers. Early
experiments with a small bronze coinage in Al-Andalus in the time of
the governors were soon abandoned, and there were also some