By the 18th century, the decline was unmistakable. The lavish palaces, once filled with life and splendor, became increasingly desolate, overshadowed by the weight of debts and mismanagement. The last Duke of Osuna, Don Pedro Alcántara Téllez-Girón y Pimentel, witnessed the disintegration of the family legacy, ultimately leading to the sale of the family estates to pay off creditors.
Today, the Casa de Osuna stands as a poignant reminder of the fleeting nature of wealth and power. Its history serves as a cautionary tale of how the pursuit of opulence can lead to one's downfall. The remnants of its former grandeur are a testament to a glorious past that, while once vibrant, now echoes with the tales of its decline.