By the late fifteenth century Ottoman Turkish mastery of the Eastern Mediterranean was nearly complete. However, the tiny island of Rhodes, just a few kilometres from the south-west coast of Turkey, remained a thorn in their side. Home to the walled headquarters of the Knights Hospitaller, a crusading Order of "warrior monks", Rhodes was besieged for three months by the full might of the Turkish army and artillery in 1480, but emerged undefeated. The Ottomans would inevitably return, so the Hospitallers strengthened and adapted their fortifications and defences in preparation for another siege. The Ottomans attacked again in 1522 and, after six months, captured Rhodes but were unable to defeat the Hospitallers who were allowed to leave with their lives, arms and possessions. Why were the Knights Hospitaller able to remain undefeated against the most powerful military force in the world? And what changes were made to the fortifications of their island stronghold? This book uniquely uses the eyewitness accounts, surviving guns and extant walls to deconstruct the story of these two sieges in detail, and uses these events as a backdrop to explore the wider relationship between the development of gunpowder weapons and the fortifications built to defend against them. Including detailed appendices with a wealth of images of the cannon and walls, this book will fascinate not only visitors to Rhodes, but also those who are interested in the art of medieval warfare.