186 EARLY MEDIEVAL SPAINIn fact the Umayyads turned the potential weaknesses of their
position to their greatest advantage. The very disunity could be made
a great source of strength. The feuding amongst the Arabs before the
arrival of 'Abd al-RaQman I had, as in Syria and Iraq, been brought
under control by keeping the opposing parties geographically sepa-
rate, and also by careful composition of armies. Conversely, the exist-
ence of adjacent groups of different racial origin or religious conviction
could serve as a restraint on the ambitions of governors or the power
of potential rebels. So great was the strength of local hostilities and
feuds, as for instance in Merida, that it was impossible for a rebellious
wali (governor) to unite all elements of the population behind him.
Many of the early Umayyads proved competent in the playing off
of local antagonisms in undermining revolts that they were unwilling
or unable to confront directly. They could also change their support
quite cynically, as best suited their interests. Thus 'Abd al-RaQrnan I
came to power principally thanks to the assistance of the Yemenis,
but by the late 760s he had turned against them. Likewise in 889,
during a revolt that involved virtually the whole of the lower
Guadalquivir valley, the amir 'Abd-Allah first depended upon the
support of the muwallads of Ecija to oppose Yemeni rebels, but sub-
sequently ordered his generals to execute their leader in order to
gain the allegiance of the Arabs of Carmona.^3
Particularly violent were some of the conflicts between the Berbers
and the indigenous population, exacerbated by racial hostility and
insecurity. In 794 a virtual civil war broke out in Tarragona, in the
course of which many of the citizens were massacred by the Berbers,
who in tum had to be suppressed by an Arab army. In the aftermath
the city was left abandoned for seven years, only being reoccupied
after the Frankish capture of Barcelona in 801, which itself may been
a consequence of the dispersal of the Berber garrison of Tarragona.^4
How far the Umayyads deliberately fostered such antagonisms is
unclear, but they were certainly quick to take advantage of them.
They could on occasion take particularly forceful measures to elimi-
nate those regarded as potential rebels and to dissuade others.' The
most notorious of these episodes was 'the Day of the Ditch', of 16
November 806, when, on the orders of the amir Al-I:Jakam I, 5,000 of
the leading men of Toledo are recorded as having been massacred at
a banquet held by the city's governor. The number of those slain may
be exaggerated and the effects were fairly short-lived, but Al-I:Jakam
earned a reputation for this and 'the Massacre of the Suburb' as 'a