Charlemagne
Cnut the Great (The English Monarchs Series)
The Carolingians : A Family Who Forged Europe
Æthelred: The Unready (English Monarchs)
Heart of Europe: A History of the Holy Roman Empire
The Capetians: Kings of France 987-1328
The Holy Roman Empire: A Thousand Years of Europe's History
The Thirty Years War: Europe’s Tragedy
On Grand Strategy