Monreale's splendid cathedral is lavishly executed with mosaics depicting events from the Old and New Testaments. After the Norman conquest of Sicily the new princes showcased their ambitions through monumental building projects. William II (1154–89) built the church complex with a cloister and palace between 1174 and 1185, employing Byzantine craftsmen. The result was a glorious fusion of Eastern and Western influences, widely regarded as the finest example of Norman architecture in Sicily.
The major attraction is the 68,220 square feet of glittering gold mosaics decorating the cathedral interior. Christ Pantocrator dominates the apse area; the nave contains narratives of the Creation; and scenes from the life of Christ adorn the walls of the aisles and the transept. The painted wooden ceiling dates from 1816–37. The roof commands a great view (a reward for climbing 172 stairs).
Bonnano Pisano's bronze doors, completed in 1186, depict 42 biblical scenes and are considered among the most important of medieval artifacts. Barisano da Trani's 42 panels on the north door, dating from 1179, present saints and evangelists.