Ten major wars of mediaeval and modern times:
- Norman Conquest, 1066 (France vs. England)
- Bishops' Wars, 1639-40 (English vs. Scotland)
- Napoleonic Wars, 1800-15 (France vs. other European powers)
- World War II, 1939-45 (British Commonwealth, United States, Soviet Union, China, and the governments-in-exile of France, Poland, and other occupied European countries vs. Germany, Italy, and Japan, and their allies)
- Gulf War, 1991 (U.S. and allies vs. Iraq)
- Thirty Years' War, 1618-48 (France vs. Hapsburg rulers)
- American War of Independence, 1775-83 (Great Britain vs. British colonies in North America)
- Spanish Civil War, 1936-9 (Republicans vs. Nationalists)
- Falklands War, 1982 (United Kingdom vs. Argentina)
- War of the Roses, 1455-85 (House of York vs. House of Lancaster)
Yikes! Getting this one in right under the wire. I'm not used to having a social life.