In 1015 and again in 1016, forces from the taifa of Denia, in the east of Muslim Spain (al-Andalus), attack Sardinia and attempted to establish control over it.
In both these years, joint expeditions from the maritime republics of Pisa and Genoa repulse the invaders and preserve Sardinia as a part of Christendom.
These Pisan–Genoese expeditions to Sardinia are approved and supported by the Papacy, making them precursors of the Crusades, which will begin eighty years later.
The victors, however, turn on each other and the Pisans obtain mastery over the island at the expense of their erstwhile allies.
For this reason, the major Christian sources for the expedition primarily belong to Pisa, which celebrates its double victory over the Muslims and the Genoese with an inscription on the walls of its Duomo.
