Make a list of all key dates and their associated events/people. Make it clear, easy to read (colours help a lot) and you can stick it on your bedroom wall. I spend around 10 - 15 mins looking at it before bed, and when I wake up. I see you have done Pysc so you probably know about the subconscious advantages of studying before you sleep.
To make it easier to cram dates and events in I usually make acronym things. For example, I did French Rev last term and for the 'Storming of the Bastille' I just write down
14J89SOTB . It looks kinda dumb but the first part is the date, 14th July 1789, and you can just abbreviate the events name. The more obscure it is the more I find it memorable because I had to think, what does that mean again? Oh yeah...
Hope this helped and God bless