The assassination of Queen Hippolyta at the wedding of Arthur and Diana is the root, this we were made aware of a few weeks ago. However, we didn’t know any of the details.
Like that it is believed that Hippolyta was assassinated by Garth, close friend and ally of Arthur, at the wedding. It was, however, the Amazon known as Artemis wearing some Atlantean armor. She beat Garth and framed him for the murder, his side never to be told as Diana killed him in a rage. Hippolyta was not the target, however, she simply saw the attack in time to sacrifice her life.
The assassination was meant for Diana; And was co-plotted by Diana’s aunt Penthesilea and Arthur’s brother Orm.