From this time onwards the Humber formed the boundary between the two kingdoms. In 684 we hear of the first English invasion of Ireland, but in the following year Ecgfrith was slain and his army totally destroyed by the Picts at a place called Nechtansmere (probably Dunnichen Moss in Forfarshire).
In 684 Caliph Abdalmalik (Abd el- Melek), in order to weaken the prestige of Mecca, set himself to beautify the holy shrine of Jerusalem, and built the Kubbet es-Sakhrah, or Dome of the Rock, which still remains one of the most beautiful buildings in the world (Caliphate: B 5).
Constantine was martyred 684 by Simeon whom Constantine Pogonatus had sent to repress the movement.