In 1602 the Irish Prince Red Hugh O’Donnell sailed to Spain to ask King Philip III, his ally, for help in the face of the imminent invasion of Ireland. He died in Simancas Castle at the age of 29, and was buried in the Convent of Saint Francis in Valladolid, as he had requested in his will. This documentary analyses the importance of the archaeological excavations that took place in 2020 so as to find the remains of the Irish leader.