A century after the expulsion of Mogahid from Sardinia the Saracens still maintained themselves in the Balearic Islands, whence they continually ravaged the coasts of Catalonia and menaced the ports of southern France. After the preaching of the first Crusade, their audacity was increased by the departure of the flower of the Italian marine for the Levant, and they seem to have pushed their forays as far south as Sicily and even to have crossed the Ionian Sea and harried the shores of Greece. The terror of the Pisan name sufficed to protect the sea-board of Tuscany from invasion, but the western basin of the Mediterranean was once more overrun by Mussulman pirates; the inhabitants of the islands and especially of Sardinia lived in constant peril of attack; Majorca was crowded with Christian captives, and, in 1113, the Pisans, whose commerce had suffered severely, resolved to put an end to a state of things which was rapidly becoming intolerable. With them were leagued the Counts of Barcelona and Montpellier and the Viscount of Narbonne; while, because their enemies were also the enemies of the Cross, the enterprise received the Papal benediction.

For this expedition our principal authority is the Liher Maio1ichinus, a contemporary poem, formerly attributed to a certain Laurentius Veronensis or Vernensis, but evidently the work of a Pisan, and of a Pisan who was himself an eye-witness of many of the events which he describes. Roncioni speaks of him as “Enrico capellano dell' arcivescovo di Pisa,” and it is highly probable that we may identify him with the Henricus presbiter plebanus of the poem.