Here's a list of some of the names used in England before and around 1000 AD:
http://www.accd.edu/sac/leassist/bede.htmAS you can see, most of the names are unfamiliar.
However, after the Norman conquest of England in 1067 naming practices changed. Many of the names in use then are recognizable to us today. Here's a list from the 13th century:
http://www.s-gabriel.org/names/talan/eng13/(the names in bold are modern forms; the ones listed underneath the bold names are the forms used in the 13th century)