In order to get your students interested in England's early history, why not introduce them to early art? Here you will find links to Celtic, Anglo-Saxon, and Medieval art. Also, I included links to some hands-on activities to get your students motivated.
Email your comments to fred35@earthlink.net .

http://www.netserf.org/Art/Anglo_Saxon/ --This site has a few examples and many links to folio images, manuscript art (which I could not get to fully work, but  you may have some luck), and the  Lindisfarne Gospels.

http://village.vossnet.co.uk/p/paulkav/page5.htm   Here you will find links to how-to pages for knotwork, key patterns, and spirals.  Any one of these could lead to good class projects.

http://www.magma.ca/~fcassidy/ This site shows what happens when modern people use computers to imitate Celtic designs.  It has many good free samples that could be saved and used in a computer generated presentation.

http://www.artlex.com/ArtLex/c/celtic.html   This site has good links to such topics illuminations, jewelry, and decorations.  It has the ugliest background that I have seen, but the hard-to-read text does contain good information.

http://www.netserf.org/Art/ If you are looking for a broader scope, this is a good site because of its links to tapestries, manuscript art, and even clipart.

http://www.georgetown.edu/cball/oe/oe-art.html   Again, this is a broader scope.

http://www.fortunecity.com/bally/tipperary/41/clipart.html   Here are some samples that You will surely find a use for.