The news that officials are preparing to transport a mysterious slab of sandstone to Westminster Abbey as a key part of King Charles III's crowning left many wondering: just what is the Stone of Destiny?

The King's upcoming coronation means the revival of numerous artifacts and traditions that haven't seen the light of day for decades.

One of those is the Stone of Destiny, a hefty stone which was part of the throne at Westminster Abbey for centuries after being stolen from Scotland. Monarchs of England and then Great Britain sat upon the throne during coronation ceremonies, with the stone serving as a symbol of the Monarchy's power.

The stone is more than half a metre long, with an iron ring set into each side and a few crosses etched crudely into the surface, a far cry from the complicated carvings one expects of an ancient artifact of its significance.

Although the pinkish, pock-marked rectangle of stone, also called the Stone of Scone, looks simple, it symbolizes hundreds of years of power struggles and conflict, with true Scottish kings traditionally crowned atop the stone for hundreds of years.

In 1996, the stone was returned to Scotland officially. King Charles III's coronation will be the first time it has been brought to Westminster since then.

HOW A STONE BECAME SACRED

No one actually knows the full story of how and why this stone became such a huge symbol.

Its earliest origins are lost to time, according to Historic Environment Scotland (HES), which manages Edinburgh Castle where the stone is usually displayed. 

There are numerous legends regarding its origins, including that it dates back to biblical times and was the same stone described as being used as a pillow by a prophet. According to Historic U.K.'s website, legend contends that it was brought from Syria to Egypt to Spain by King Gathelus, whose descendant then brought the stone to Ireland. From there it moved to Scotland with the invading Scots, it is believed.

The various stories about its origins often conflict with each other and other historical facts in terms of chronology.

But history seems to agree that in 1296, after the stone had been used for hundreds of years in the coronation of Scottish kings, this ancient symbol of Scotland's monarchy was seized by King Edward I of England.

A new throne called the Coronation Chair was built to house the stone, stored on a shelf underneath the seat of the throne, and it was this throne that was used in all coronation ceremonies of the subsequent monarchs of England and then Great Britain — including the late Queen Elizabeth II.

Some stories suggest that the stone taken by King Edward I was actually a replacement, with the original Stone of Destiny hidden by monks when he attacked.

BACK TO WESTMINSTER

In 1996, the Stone was painstakingly removed from the throne to be given back to Scotland. It took conservation specialists more than six hours to carefully winch the block out of the Coronation Chair.

This wasn't the first time that Scotland tried to reclaim its property. In 1950, four students from the University of Glasgow broke into Westminster Abbey in the early hours of Christmas Day to take the stone, accidentally breaking off a corner in the process. They managed to escape back to Scotland, and three months later, the stone was discovered at an abbey in Scotland and subsequently returned to Westminster Abbey.

When the stone officially returned to Scotland in 1996, 10,000 people lined up to catch a glimpse of it on its procession into Edinburgh Castle.

Although the coronation date for King Charles III has not been officially selected, HES confirmed that the stone would travel back to Westminster Abbey for the ceremony.

After that, the group said in an emailed statement to CTVNews.ca, it will be returned to Scotland.

Correction:

This story has been updated to reflect that it was four students who stole the stone in 1950.