Fructuosus of Braga turned it into a monastery, linked to the convent of San Juan de Poyo.

[3] In the 12th century, the island of Tambo belonged to Queen Urraca and was donated to the convent of San Juan de Poyo.

In 1589 the chapel was plundered by the corsair Francis Drake, who threw the figure of Santa María de Gracia into the sea.

[4] In 1846, with the Spanish confiscation it ceased to belong to the monks of Poyo and years later it was bought by the Minister of Justice, Eugenio Montero Ríos.

[9] On 14 April 2013, a group of Combarro residents made a symbolic declaration of independence of the island as an act of protest against the state of neglect it suffered after demilitarisation.

[12][13] The island has a surface area of 28 hectares and reaches an altitude of 80 metres on Mount San Facundo.