The Ancients sought to reconnect the two worlds
An Ancient Priest sought to reconnect the worlds of the Sea of Thieves and the Sea of the Damned once more. The outcome of this remains unknown, however the Priest understood that the two worlds must remain parted to preserve the balance with a world of the living and a world of the dead.
The Ancients destroyed the Veil to prevent its power from falling into the wrong hands. They fed the headpiece to the Shrouded Ghost and hid the stones where they would never be discovered.