A royal funeral has been held in France for the co-called "lost Dauphin", the son of the beheaded king Louis XVI and Queen Marie-Antoinette.
The royal heart has been carted around Europe in a jar
A heart widely assumed to be that of dauphin Louis-Charles was laid to rest in a basilica outside Paris.
He died of tuberculosis at the age of 10 in a prison cell in 1795, two years after his parents were guillotined.
Louis-Charles's fate remained a mystery for two centuries, until a DNA test on a preserved heart in 2000.
The genetic data showed that the organ belonged to the child of Louis XVI and Marie-Antoinette.
On Tuesday it was placed near his parent's grave at the royal crypt of Saint Denis basilica, north of Paris.
More than 2,000 people - including European royalty -
attended the ceremony, which began with a funeral mass.
The test in 2000 quashed rumours that the dauphin - who would have reigned as Louis XVII - had somehow escaped from Temple prison in Paris.
The doctor who performed the autopsy on the boy in 1795 cut out the heart and kept it in an alcohol-filled vase.
He boasted of his possession to a student, who stole it.
When the student died of tuberculosis himself his widow returned the organ to the doctor, who sought to give it to France's royal Bourbon family.
He was thwarted by royal squabbles. The heart found its way to the Spanish Bourbons, and eventually back to France.
Despite the genetic test, there is still controversy about who the preserved organ belongs.
Some commentators have argued that it could belong to the dauphin's older brother, who died in 1789.