The Entire History Of The Normans Historian Levi Roach explains

From around 1000 to 1200 AD one people arguably changed Europe more than any other. Horse-backed descendants of Vikings, from England to Italy, Spain to the Holy Land they founded and transformed kingdoms wherever they went. On Today’s History Time: Unearthed we tell the story of the Normans.

Dr Levi Roach is head of history at Exeter University, author and medievalist specialising in Anglo Saxon England, the Holy Roman Empire and Europe's Middle Ages. He has written many excellent books on the period which I highly recommend.