This is a map of Britain before the Saxons arrived in their boats.  During this time, happy, nature-loving Celts roamed the land.
This is a map of the Saxon invasions.  The Saxons, Angles, and Jutes arrived from north in their boats and took over the land that once belonged to the Celts.  Here we have a major influence of Germanic in the development of the English language.
This is a map of Britain after the Romans (Ceasar) arrived in their boats.  It doesn't look much different, but believe me the language and land changed--aquaducts and roads were developed by the Romans that still exist to this day!
So the Romans got tired of Britain and Caesar got stabbed in the back so eventually they left.  This is a map of Britain during/just before the battle of Hastings.  Notice the towns on the east coast of Britain.  The towns of Hastings, Pevensey, and Dover are referred to by the English as "1066 Country" because of the Norman's (French) attack on them.  Also, interestingly about 800 years later this is the same area where allied troops left to engage in the bloody battle of Normandy (D-Day) in WWII.