The ancient world's grandest cathedral is giving up its secrets after nearly 1,500 years as archaeologists discover traces of the 'last Roman emperor' in its stones.
Built in 532AD in ancient Constantinople - today Istanbul in Turkey - the Hagia Sophia is the crowning masterpiece of Eastern Roman Emperor Justinian the Great.
Through his work rebuilding Rome and reclaiming lands lost to the empire, Justinian earned the nickname "the last Roman" from some historians.
Now, 1554 years after his death, researchers have uncovered the exact spot in the Hagia Sophia where he stood during ceremonies.
Today the emperor’s place is marked by a humble circle of stone, unnoticed amid the grandeur of the wider building until now.
Ken Dark, who has spent years studying the former cathedral with fellow archaeologist Jan Kostenec, explained that the stone was called a porphyry.
“The porphyry disc was found in, and found to be part of, the original floor of the Justinianic church and is aligned with a doorway from that time,” he said.
“Such discs are known from both archaeological and written evidence to have marked where emperors stood during ceremonies.
“Given that it was part of Justinian’s Hagia Sophia, it must have been where that emperor was intended to stand – and presumably stood – during a religious ceremony.”
He continued: “The exact ceremony involved is uncertain, but this would have been somewhere he stood with clergy and members of the court rather than in full view of the wider congregation.
“It is a smaller enclosed space than the vast area beneath the dome, suitable for more private devotions and liturgy.”
Its one of a number of discoveries set to “revolutionise” our understanding of the ancient building, according to Dr Dark.
The University of Reading professor said they had unearthed the original baptistery where the imperial family would have baptised their children.
On top of that, another part of the building thought to have been a later Ottoman addition has been shown to be far older.
Archaeologists now believe that the northwest vestibule was built when Justinian still reigned over the Eastern Roman empire, which today is known as the Byzantine empire.
“The wall of the vestibule is bonded into – and therefore demonstrably built at the same time as – the adjacent, well-dated, original wall of Justinian’s church of Hagia Sophia,” he said.
Dr Dark concluded: “This new material revolutionises understanding of the Byzantine-period Hagia Sophia complex.
“It requires major revision to common understanding of the plan of the sixth-century church itself.”
The Hagia Sophia served as a Christian cathedral from its completion in 537AD until 1453, when it was converted into a mosque by its Ottoman conquerors.
The building continued as a mosque until 1931, before reopening in 1935 as a museum, which it has remained since.
However, Turkish president Recep Erdoğan has publicly raised the idea of converting it back into a mosque.
All the team’s discoveries at the site are revealed in the new book, Hagia Sophia in Context: An Archaeological Reexamination of the Cathedral of Byzantine Constantinople.