While the Palace of the Grand Masters looks like one big, solid building from the outside, in reality it is an amalgamation of four distinct buildings that stood there before it became the Palace.

There was the auberge of the Italian knights (one storey high, as were all the auberges to begin with, the only one to remain single-storey being the Auberge of Aragon), a house belonging to two Italian knights, brothers by the name of Bosio, and another house purchased by Eustachio del Monte, whose uncle later became Grand Master.

Originally, the Palace of the Grand Master was intended to be built where the Auberge de Castille now stands, although in the years before the Great Siege, when Valletta was being designed, Bartolomeo Genga planned for it to be in the exact centre of the city, as it is today.

Grand Master del Monte went to stay in his nephew’s house, and when the nephew died, the Grand Master refused to move. He persuaded the Italian knights to find another site for their auberge, bought the house belonging to the Bosio brothers and joined together the four buildings.

Successive Grand Masters did their bit to make unite the building as a whole. But if one descends below street level, one can clearly see the delineations of the four distinct houses, said architect Edward Said, speaking last Monday in the second lecture of the series hosted by Salvator Mousu regarding the palace, to a very full hall, despite the cold and threatening rain.

The palace basement is full of mysteries – a sort of underworld, Mr Said explained and it is easy to become disoriented down there, because you quickly lose track of which direction you are facing.

One of the most remarkable discoveries is a pile of telegraph poles stacked one on top of the other. No one knows for sure why they were put there, but it seems this was done in the years preceding World War II to counteract humidity. What happened instead is that the poles are rotting and are causing subsidence around them.

Another discovery is a circular room deep underneath the palace, which is accessed through a series of steps. It may originally have been one of the palace’s cisterns, but it seems to have been turned – again in World War II – into a strong room.

Reports that Churchill and Roosevelt held some of their meetings down there seem improbable.

A member of the audience, with what seemed personal knowledge, said this room held the treasury of the Government Savings Bank on the other side of St George Square.

Perhaps the most significant of the discoveries was something merely hinted at by Mr Said: that not all the discoveries made during the restoration of Palace Square – or St George’s Square – have as yet been made public, and that this discovery was related to before the Great Siege.

Mr Said also spoke about Palace Square, in particular the archway in Archbishop Street, facing the former Civil Service building (on top of which the runaway container truck broke through the railings just a few days ago before coming to rest across the road on the Police Station façade). This archway is one of the earliest arches in Valletta, dating to the time when St John’s Co-Cathedral was being built.

The square is criss-crossed with tunnels, but one was certainly the tunnel for the Fontaniere, the knight who was in charge of the water system in Valletta and the public fountains, so that he could switch on the fountain in the square. Significantly, the Fontaniere, who happened to be a French knight, kept his role during the time of the French occupation.

When Grand Master Wignacourt built his aqueduct to bring water from Rabat to Valletta, he also built a huge cistern for this water next to City Gate. This was on top of the railway station and was destroyed in the 1960s during the building of City Gate and the creation of Freedom Square.

Persistent reports that it was the British who removed the fountain in the square so that they could hold their military parades are not true, said Mr Said, because there are paintings of the square in the times of the knights that show no fountain. This fountain is now to be found in St Philip’s Garden in Floriana.

Another discovery made during the square’s restoration showed that there is no cistern underneath the square, so hopes that it could be turned into an underground car park were unfounded.

The next lecture in the series will be on Monday, 30 December when Dr Alfred Bonnici will speak about the political developments in the Tapestry Chamber since 1921.