Philip II ruled France with an iron fist for over 40 years, expanding its borders and increasing its power. For his entire reign his counterpart on the English throne was a member of the Plantagenet dynasty, and Philip took on them all: Henry II, Richard the Lionheart, John and Henry III. And yet we know so little about medieval England’s greatest enemy.

Historian Catherine Hanley, author of the critically acclaimed 1217, redresses this imbalance, bringing Philip out of the shadows in this fascinating new history. Delving into French medieval archives, Nemesis explores Philip’s motives for attacking England and in doing so we learn not only about him but discover so much more about England’s most colourful and controversial of rulers – the Plantagenets.

When Philip first succeeded to the throne in 1180, Henry II of England, thanks to his Angevin and Norman ancestry as well as his wife’s inheritance of Aquitaine, ruled more of France than Philip himself. By the end of Philip’s reign in 1223, the pendulum of power had swung the other way. Nemesis reveals how Philip exploited the constant familiar squabbles of the Plantagenets to secure his grip on France, his wily political manoeuvring combined with a mastery of the medieval battlefield turning France into a powerhouse of Europe.

In 1215 King John had agreed to the terms of Magna Carta, but then reneged on his word, plunging the kingdom into war. Rebellious barons offered the throne to the French prince Louis and set off a chain of events that almost changed the course of English history.

Louis arrived in May 1216, was proclaimed king in London, and by the autumn had half of England under his control. However, the choice of a French prince had enormous repercussions: now not merely an internal rebellion, but a war in which the defenders were battling to prevent a foreign takeover. John’s death in October 1216 left the throne in the hands of his 9-year-old son, Henry, and his regent, William Marshal, which changed the face of the war again, for now the king trying to fight off an invader was not a hated tyrant but an innocent child.

1217 charts the nascent sense of national identity that began to swell. Three key battles would determine England’s destiny. The fortress of Dover was besieged, the city of Lincoln was attacked, and a great invasion force set sail and, unusually for the time, was intercepted at sea. Catherine Hanley expertly navigates medieval siege warfare, royal politics, and fighting at sea to bring this remarkable period of history to life.

The sons of Henry II and Eleanor of Aquitaine have been the subject of much historical attention, but their daughters have been curiously overlooked. The youngest of them, Joanna, led a particularly extraordinary life full of adventure and danger – and not a little controversy – that was more than a match for those of any of her brothers, including the famed Lionheart himself.

Lionessheart is Joanna’s story, and also an exploration of the wider world of the twelfth century as seen through the eyes of a woman who was a princess and a pioneer, a warrior and a wife, a captive and a queen.

The twelfth and thirteenth centuries were a time of personal monarchy, when the close friendship or petty feuding between kings and queens could determine the course of history. The Capetians of France and the Angevins of England waged war, made peace, and intermarried. The lands under the control of the English king once reached to within a few miles of Paris, and those ruled by the French house, at their apogee, crossed the Channel and encompassed London itself.

In this lively, engaging history, Catherine Hanley traces the great clashes, and occasional friendships, of the two dynasties. Along the way, she emphasizes the fascinating and influential women of the houses-including Eleanor of Aquitaine and Blanche of Castille-and shows how personalities and familial bonds shaped the fate of two countries. This is a tale of two intertwined dynasties that shaped the present and the future of England and France, told through the stories of the people involved.