Revenge as poetry and poetry as revenge.

The bad name of the Umayyd dynasty(661-750, 756-1031 in Iberian
peninsula) comes from a very simple fact: They lost. And the history
was written by the victors. The written works that have come to us
from the Umayyd dynasty of 661-750 have dubious legitimacy - they
may be fakes written by the supportes of the Abbasid caliphate
(750-1258, after the Mongol invasion they lived in Egypt as the puppets
of the rulers of Egypt until 1517, when the Ottomans destroyed the
Mameluk Empire in Egypt and Syria).

This is very typical; one has to remember China, where because of the
Mandate of Heaven every succesful founder of dynasty had to be
described by as a great hero and last ruler of every dynasty was a
monster, or at best a weak ruler, who was justifiably overthrown.
And the first things a new dynasty did was to start the writing of the
official history of the preceding dynasty: From the hero to the monster.