Merlin's Descendants, Book One. Merlin's daughter must help her father and King Arthur show warring barons and invading Saxons that Honor, Truth and Promises are meant to be kept.
Merlin's Descendants, Book Five. 1763: all of Europe is at war and the Turks are storming toward Vienna. The magical protection of Britain requires that Georgina Kirkwood leave the secret Pendragon Society and disguise herself as a man to fight for England.
Merlin's Descendants, Book Four. Mary Queen of Scots is dead. The Spanish Armada is gathering. The children from Guardian of the Vision must battle corrupt politicians, the Church, and El Lobison, the master of all werewolves, to save England.