Although the usual proviso: salva fidelitate imperatoris was duly inserted in the treaty with Florence, it was qualified by the addition of a clause which practically provided for the maintenance of the alliance even in the face of Imperial disapproval: ita tamen vt imperator non possit liberare nos a predictis sacramentis. Neither did that alliance stand alone. Already, in 1169, the Pisans had made peace with William of Sicily, and, in 1168 or 1169, they had sent ambassadors to Constantinople to treat with Manuel Comnenus. The negotiations were long and difficult, lasting, as Marangone tells us, for over three years; and only when they had agreed to annul every pact inconsistent with their loyalty to the Eastern Empire, with whomsoever entered into—coronato vel non coronato—were the Pisans at last permitted to re-occupy the quarter from which they had been expelled some ten years earlier.

This change in Pisan policy was eagerly seized upon by her enemies as affording an opportunity to discredit her with Barbarossa; and, in the late autumn or early winter of 1171, “rogatu et suasione et precibus Lucensium et Ianuensium,” Christian of Mayence was appointed Imperial Legate of all Italy, and unexpectedly appeared in Lombardy. He traversed the territories of the revolted Communes with all possible speed, avoiding the more frequented roads, and, after fording the Tanaro near Alessandria, reached Genoa in safety.