I’m standing between two prize fighters in the middle of Istanbul. They’re staring each other down like Sumo wrestlers preparing to clash in an earth-shattering explosion of salt and dust.

In one corner crouches Haghia Sophia, the Byzantine Church of the Holy Wisdom, a huge, squat building that was once the toast of the Christian world. You can almost sense it tugging at the four slender minarets driven into its corners like restraining stakes to keep it firmly in place, as if it were a great moody bear.

Perhaps this is the reason it glares with such smouldering resentment at its opposite number, the more gracile and complacent Sultanahmet Camii. This elegant Ottoman mosque with its six imperial minarets sits serenely across the park with its new public seating and ornamental fountain. It seems to whisper tauntingly in soft Eastern tones, ‘Come on, then, if you think you’ve got it in you.’

Where the mosque rests content in the assurance of its present mastery, the great old church spends its time dreaming of past glories.

Tourists scuttle about its feet like so many ants and stand in queues patiently waiting to inspect its ancient mosaics. At prayer times all the city’s mosques, led by Sultan Ahmet Camii, unite in taunting it with prayers to Allah which it has after almost six centuries learnt to ignore for the most part.

Whenever I come to Istanbul I feel sorry for this venerable old building. It’s trapped in the wrong time, like a decrepit old lady who was once the toast of society for her unrivalled beauty and vitality, who had her pick of suitors and wore the finest jewels to state occasions.

Now all her generation has long been swept away and she’s completely alone, a mere curiosity for visiting strangers who mean absolutely nothing to her. Passing out of the blinding sun and into this vast, cool interior of shadows and glittering mosaics you feel like Pip in Great Expectations entering the dark, cobwebbed world of Miss Havisham.

I feel like giving her a hand to end it all, but where would you start administering voluntary euthanasia to a building this big? She’s over 1400 years old, born in 558AD under the Emperor Justinian after several other churches on the same site were damaged by various natural and man-made disasters.

By now she’s taken such firm root that nothing could shake her. She was left completely untouched and no doubt equally unmoved by the major earthquake that flattened much of Istanbul in 1999.

One thing that might just have cheered her up recently and reminded her of happier times was the rediscovery of parts of the mosaic flooring of the old Great Palace that once stood right next to her. That was in the glory days, when the Emperor and his family would come out onto the palace balcony just to her left, overlooking the Hippodrome with its Egyptian obelisk and spinning gold dolphins, to watch the chariots race by.

This by now almost totally lost imperial palace extended from Haghia Sophia and the Hippodrome right down to the coast, where the great sea wall of the city was lapped by the waters of the Marmara.

Constantine I came here in 324AD and decided to make the small and insignificant Greek town of Byzantium his new capital in the East, to replace Rome in the West. He immediately started a large-scale public works programme which included his own palace, the Palatium Magnum, to be built on Seraglio Hill in what is now the Istanbul district of Sultanahmet.

This was done with the deliberate intention of acting as a counterweight to the Palatine’s imperial buildings in Rome, and it remained the seat of government here until the 20th century.

A long and glittering succession of Byzantine Emperors and Ottoman Sultans took up residence, and this small area must have witnessed some world-class intrigues, coups and murders in its eventful and frequently steamy and gruesome history.

It’s an important site for prospective archaeological finds, but experts labouring here since the 19th century have encountered major problems in their ongoing attempts to locate, excavate, date, explore and reconstruct the numerous buildings that constituted the Palace District.

This is mainly because the majority of the Byzantine ruins lie deeply buried beneath subsequent Ottoman buildings and various other structures, as well as tons of dirt.

The main clues about where the Great Palace structures are hidden come from a written source, the Book of Ceremonies from the court of Emperor Konstantinos VII Porphyrogennetos, who reigned for 15 years from 944AD. This book includes a number of names and locations of palaces and has descriptions of their interiors.

The problem is that today the site as it stands is devoid of any topographical fixed points. Despite their undoubted monumentality, those venerable old buildings have left very few traces – a salutary lesson in vanity and humility, no doubt, but also a definite pain in the neck for historians and archaeologists.

We do know that already under Constantine the Great (306-337AD) the palace quarter was composed of various adjoining buildings. These included throne rooms, spacious courtyards, audience chambers, churches, chapels, gardens, fountains, libraries, thermal baths, assembly buildings and stadiums. Put together these all formed a rambling, indeed Byzantine, palatial complex.

Over the many long centuries of Byzantine rule, this complex underwent numerous additions, repairs, conversions and extensions. There is a difference in height between the Sea of Marmara and the Hippodrome of 32.5 metres and this necessitated for example the construction of a series of substructures and vaults. In all, the palace buildings are thought to have risen up on a set of six terraces.

The Chalke, a great bronze gate, occupied a site on the eastern edge of the area between Haghia Sophia and the Blue Mosque and led into the senate building and the Magnaura.

This palace contained amongst other things a magnificent and apparently miraculous throne which rose into the air when the emperor took his seat on it before astounded visiting dignitaries. It was actually worked by a system of gears and hydraulics, and it wasn’t until the European Renaissance many centuries later that the world would see this sort of man-made marvel again. In England at the time Anglo-Saxon chieftains were still holding court on wooden benches.

Just to the southwest were the barracks of the palace guard, along with the Scholae and the Triclinium where applicants would gather to petition the emperor on various matters.

The imperial state rooms and private apartments were located further to the west of these. Here, there was a suite of large adjoining rooms that made up the Daphne and Kathisma Palaces, which had an imperial box overlooking the race track.

Another palace in the greater complex of buildings was the Palace Aula, excavated in 1935-1954, and the magnificent mosaic floor and wall decorations from this building are a major tourist attraction today. They’re housed in the Mosaic Museum just next to Haghia Sophia. The museum was built around them, so these are in-situ floors that bore the weight of countless Byzantine functionaries and royalty.

One part of the old palace complex that most visitors never see is the Bucolean Palace, which was built on the lower terraces next to the imperial harbour to the southwest of the main buildings.

All that remains of this today is a crumbling but evocative stone wall and three large windows complete with marble lintels. It’s a wonder that these are still standing. Sitting in the small park in front of them in the cool quiet of an evening it’s possible to feel very close indeed to the long lost Byzantine rulers, their families and courtiers.

It’s enough to make me wax poetical with a few lines from Omar Khayyam:

The arch is broken and the splendour fled
Where every aspect once was brave and fair,
This Palace none inhabits save the dead
Whose ivory bones the desert breezes stir.
The Hall of Audience desecrated lies –
Though Princes came to make obeisance here –
And from a ruined tower an owlet cries:
‘The glory is departed – Where? Where? Where?’

 The Great Palace was eventually abandoned by the emperors in favour of the more secure and comfortable Blachernae Palace in the northeast quarter of the city.

When Mehmed the Conqueror entered Constantinople in 1453 following a long siege he was apparently deeply saddened at the Great Palace’s state of neglect.

A Turkish chronicler of the time reported that the Sultan, surveying its crumbling walls and vacant windows, was moved to recite lines by the Persian poet Saadi:

‘The spider is the curtain-holder in the Palace of the Caesars.
The owl hoots its night call on the Towers of Afrasiab.’

Mehmed, despite having his contemplative moments, was no softie and he gave the city over to his victorious troops for the traditional three days of rape, pillage and massacre before settling in to his new address.

Haghia Sophia had her frescoes and murals plastered over and minarets added to turn her into a mosque, and the abandoned Great Palace next door was left to gradually subside into the spoil heap of history.

Only now is it slowly returning to the light of day, rising like a fabulous beast from the ashes of the ages.

Nowhere in antiquity do we possess a tessellated floor of quite the size and quality of the Great Palace mosaic in Istanbul. Who knows how much of the glittering, fabled magnificence of the Byzantine emperors is left to discover there, hidden beneath the dust of long centuries?