In 1174 and 1175 he made treaties with Genoa and Venice and his marriage in February 1177 with Joan, daughter of Henry II.
In 1899 the average size of the farms was 1174 acres.
Alessandria was founded in 1168 by the inhabitants of the district in order to defend themselves against the marquis of Monferrato and the town of Pavia, at whose request it was besieged in 1174 by Frederick Barbarossa for six months, but without success.
On the death of the ex-caliph he was confirmed in the prefecture of Egypt as deputy of Nureddin; and on the decease of the latter in 1174 (12th of April) he took the title sultan, so that with this year the Ayyubite period of Egyptian history properly begins.
In 1174 Nur-ed-din died, and the period of Saladin's conquests in Syria begins.
However, when ravaging the country near Alnwick, William was taken prisoner in July 1174, and after a short captivity at Richmond was carried to Normandy, where he soon purchased his release by assenting in December 1174 to the treaty of Falaise.