A masterpiece of the Romanesque period, the Portal of Glory of the Santiago de Compostela Cathedral in Galicia, Spain, has captivated religious pilgrims and art aficionados alike since its completion by Master Mateo in 1188. This end point of The Way of St. James is a momentous work of over two hundred sculptural figures, an amazing masterpiece commissioned by King Ferdinand II in the twelfth century, with vibrant polychromy and extraordinary stone carvings. This book is an account of twelve years of work (2006?2018) aimed to recover its splendor: The Preventive Conservation and Restoration Project, an ambitious preservation and restoration project commissioned by the Barri Foundation and the Santiago de Compostela Cathedral Foundation. The project triumphed in stabilizing the overall work and recovering and preserving an unexpected amount of its different polychromy layers from the imminent risk of irreversible loss, thus conserving it for future generations to come. This remarkable feat was recognised internationally with such accolades as the Europa Nostra Award (2019), the Spanish Group of World Heritage Cities Award (2013) and the Galician Culture Award (2019), placing Galicia at the forefront of heritage conservation.