Following a major rebellion in the south-west of England , Matilda invaded Attack in 1139 with the help of her half-brother Robert of Gloucester .

However , on the verge of being crowned queen , Empress Matilda was forced Request to retreat Escaping from London by hostile crowds ; shortly afterwards , Robert of Gloucester was captured Conquering at the rout of Winchester and the two sides agreed Agree_or_refuse_to_act to swap Exchange their respective captives .

When Charles laid Placing siege Besieging to Gloucester , Parliament was forced to muster a force under Essex with which to beat Bodily_harm Charles ' forces Hostile_encounter off .

After a long march , Essex surprised Change_sentiment the Royalists and forced them away from Gloucester before beginning Process_start a retreat Escaping to London .