Palermo Cathedral was erected in 1185 by Walter Ophamil (or Walter of the Mill), the Anglo-Norman archbishop of Palermo and the Norman King William II’s minister. One of his close relatives had Monreale cathedral built during an overlapping time period, and they were therefore regarded as competing with each other for glory.

The Normans had only just taken Sicily from the Moors, and relied on their skill as architects. Despite being far more European-looking than Monreale Cathedral, the cathedral of Palermo is still Europe’s only Cathedral with palm trees growing in its forecourt and, more interestingly, the only cathedral in the world with a passage of the Koran carved into one of its pillars, and into a plaque on one of the external walls.

It was put there as a sign of friendship and reassurance to the Muslim builders that they would be safe under the new Catholic government, since many of the Muslims had been driven out. This new cathedral they were building was on the site of a grand mosque which, under Moorish rule, had housed 7,000 worshippers. The mosque had been built on the site of the previous church, which the Moors had demolished; and when the Normans arrived, they demolished the mosque and were determined to build a more impressive cathedral in its place.

So, more than competing with his cousin, King William was competing with his Muslim predecessors.

This cathedral also contains the first ever statue erected in honour of English Saint Thomas a Beckett, murdered in Canterbury Cathedral. He spent five years living in Sicily in exile, where he was a favourite of the Norman rulers and dearly loved by the entire population. In Marsala on the far western tip of Sicily (where the lovely wine comes from) there is a whole cathedral dedicated to him. It is a pity he returned to England, thinking relations with the king could improve, only to be murdered.

Palermo cathedral had a hole drilled into one side of the cupola by a scientist in 1690, which meant he could turn the entire thing into a colossal sundial that works as a calendar all year round and maps the different constellations used by astrologers.

It is called a heliometer (solar “observatory”), one of a number built in Italy in the 17th and 18th centuries. Essentially a tiny hole in one of the minor domes acts as pinhole camera, projecting an image of the sun onto the floor at solar noon (12:00 in winter, 13:00 in summer). If you visit, look for a bronze line set into the floor at a jaunty angle with your star sign somewhere along it. It is called la Meridiana and it runs precisely north-south, so it is actually very logical, even though it looks very squiffy inside the cathedral. The ends of the line mark the positions as at the summer and winter solstices; signs of the zodiac show the various other dates throughout the year.

Its purpose was to standardise the measurement of time and the calendar. The convention in Sicily had been the ancient Roman one, in other words, that the day was measured from the moment of sun-rise. The Sicilians were using 24 hours and including night-time whilst the Romans used six flexibly long hours and didn’t count time when it was dark, but despite these refinements, Sicily still had no two locations with the same time. This made shipping tricky, but the scientist who designed the whole apparatus persuaded the archbishop to permit it by pointing out that a proper calendar would mean the Vernal Equinox could be timed accurately and thus provide the correct date for Easter.

There is a large priest school adjacent to the cathedral, and a raised walkway like a bridge of sighs which links the second floor of the school to an the upper level of the cathedral. Legend has it that this was built so the trainee priests would not have to walk in the streets and run the risk of having their thoughts sullied by the sight of a woman.

Here follows a Palermo Cathedral gallery.