Chronicles of the Four Courts Series by Brantwijn Serrah

The changeling princesses of the Springtime Elves share a unique bond with their Knight — a bond that must remain perfectly secret. When the queen of the elves discovers their passionate love, she curses and exiles Finn from the elfin lands forever. With their guardian sent away to a lifeless wasteland, the royal changelings have no defense when the unseen enemies of the Four Courts attack, and the House of Elves falls... moreThe changeling princesses of the Springtime Elves share a unique bond with their Knight — a bond that must remain perfectly secret. When the queen of the elves discovers their passionate love, she curses and exiles Finn from the elfin lands forever. With their guardian sent away to a lifeless wasteland, the royal changelings have no defense when the unseen enemies of the Four Courts attack, and the House of Elves falls. To save his loves, Finn will need to break out of prison, undertake a perilous journey across the lands of Thairy, face wicked creatures, rogue Knights, and one of the most dangerous monsters in the fae world. The enemy will soon learn what it means to provoke a true Son of War. less