Constantinople as such no longer exists (it is now Istanbul) and at first glance it's not easy finding out what the Great Palace might have been like. It certainly took up a lot of space, and most of it lies beneath modern Istanbul. It was sited on the peninsular bordered by the Sea of Marmara and the Golden Horn. A city in itself, there were dozens of buildings in the Great Palace, which included residential palaces, baths, stables, a garrison, banqueting halls, churches. There's even a polo ground - the hero of this novel is a keen polo player...
There are maps that give an idea of the scale of the Great Palace. The one below is from Wikipedia. The Imperial Palace was separated from the rest of the City by vast walls. It was guarded day and night. You can see from this section of the map that some of the buildings overlooked the sea. The women's quarters, where Princess Theodora has her apartment, is in this area of the palace - it was known as the Boukoleon Palace.
As one would expect, there's a distinctly twelfth century look to the Tower of London furnishings and the colours - red rather than Imperial purple - are not quite right, but they do give a feeling of luxury.
The last picture shows a painted shutter. Shutters have been used for centuries to keep out the wintry blasts, and they would be equally useful in a palace overlooking the Sea of Marmara as in one overlooking the River Thames!
For more about Betrothed to the Barbarian, please see the monthly release list for August, or visit my blog site: Carol Townend.