Complex sentence: The recorded history of the diamond dates from the 12th century, when it was first acquired by Eleanor of Aquitaine, between 1137 and 1152, making the Briolette of India perhaps the oldest diamond on record in the world.
Split into simpler sentences: The recorded history of the diamond dates back to the 12th Century when it was first acquired by Eleanor of Aquitaine. This was between 1137 and 1152, making the Briolette of India perhaps the oldest diamond on record in the world.