The resources below will help you understand the factions and individuals involved in this complicated dynastic struggle.
This "extremely brief history of the Wars of the Roses" by Ruth Anne Vineyard is an excerpt of a research seminar curriculum and provides a clear and concise introduction to the complicated wars.
Substantive overview of the causes and progress of the war is accompanied by an extensive genealogical tree, at Wikipedia.
Timelines, brief bios and capsule overviews of the battles highlight this site.
Nice effort includes a lucid introduction to the origins of the conflict, descriptions of battles, important people and more.
Extensive description of the battle by D. John Saddler at
Military History Magazine, online at TheHistoryNet.
Reconstructed map of Bosworth Field with positions of Henry Tudor's and Richard III's armies, online at Lara Eakins' Tudor England site.
An enlightening article by Margaret Gurowitz at the Richard III Society examines the few facts truly available to us and looks at different interpretations of what we know.
