Workers restoring a gothic palace have discovered the sarcophagus of a five-year-old girl who was buried there up to 800 years ago.

The archaeologists were restoring ceramic tiles in the chapel of the Alcazar of Seville in the southern Spanish city of Seville when they stumbled upon the lead sarcophagus containing a wooden coffin with the girl’s remains under the chapel’s altar.

Professor Miguel Angel Tabales from the University of Seville, 56, is the director of the archaeological project’s team. In an interview about the project with Real Press, he said: “It was part of an intervention to know if it is possible to build an air chamber in the walls of the Gothic Palace to restore the ceramic tiles dating back to 1577.”

He said the tiles were “in a bad state of preservation, but they are unique,” adding that discovering the ancient sarcophagus has meant changing his restoration strategy considerably.

Archaeologists examining the small burial container and its contents believe the girl, found with her arms crossed over her chest, was aged around five at death and comes from an important family as she was buried under the great altar of the chapel – a privilege offered only to those of high birth.

Antonio Munoz, the delegate of Urban Habitat, Culture and Tourism of the city council of Sevilla, said in a press statement obtained by Real Press that this theory fits with the hypothesis by Professor Tabales that there is an undiscovered crypt under the Chapel.

The professor said he believes there could be a crypt underneath the chapel as it is situated well above the previous building site, and this theory will eventually be tested by ground-penetrating radar tests.

He added that preliminary investigations reveal the girl’s remains probably date from the 13th or 14th century but carbon testing will confirm this.

Though the lead sarcophagus has preserved well, the wood coffin and its contents are not in such good condition as Professor Tabales suspects the sarcophagus was breached in the early 20th century during repair works on the chapel’s floor.

He said the lead of the sarcophagus helped protect its contents but the remains started to deteriorate when exposed to air in the early 1900s, and while the bones remain in a good state of preservation the exposure could affect DNA testing.

Despite this, some of the girl’s hair remains and the coffin also contains remnants of fabric, shoes, leather and buttons.

Professor Tabales said it is as yet unknown how the girl died, but commented there are no signs of violence inflicted upon her, and she was buried in a privileged style with Christian traditions.

Future tests and analyses on her remains will hopefully reveal more about her lineage, date of death and geographic origins.

The palace was built in gothic style on the former site of an Islamic fortress on orders from Alfonso X El Sabio (Alfonso the Wise) and represents the triumph of Christian ideology against the 800-year Muslim rule of Seville.

Professor Tabales said the monarch lived in the Alcazar of Seville after defeating the city’s Muslim ruler and the historic palace has been altered many times since, such as the Mudejar-style tiles that were added in 1577.

It is located in the Royal Alcazar of Seville, which was declared a UNESCO World Heritage site, along with the adjoining Seville Cathedral and the General Archive of the Indies, in 1987.

The impressive palace has featured in the fifth and sixth season of the blockbuster series, Game of Thrones, and the 1962 movie, Lawrence of Arabia.