The exact date of the invasion is disputed; Zosimus placed it after the Battle of Naissus and before the death of emperor Claudius, which sets it in the summer of 270.[1] Other historians such as Watson have dismissed Zosimus' account, places the invasion in October 270.[3] According to Watson, the invasion of Egypt was an opportunistic move by the queen, encouraged by the news of Claudius' death in August.[2][9]