In the National Archives of the Torre do Tombo in Lisbon, the Persian documents of 16th-17th centuries are selected and preserved, in general, under a large category, called before "Cartas Orientais" or "Documentos arábigos" and, currently, "Documentos Orientais". This collection forms a part of the funds of the "Manuscritos da Casa dos Tratados". Some of these documents pertain to the Portuguese, in continuation of their policy of expansion in the Indian Ocean and the Persian Gulf in early 16th century who had reached the island of Hormuz, situated at 6 km from the Iranian coast. This great transit market of the Persian Gulf had then a population of approximately 40.000. Called until the 13th century "Jarun", the island of Hormuz belonged to Iran and the rich "kingdom" of this island had for centuries depended on the central government of Iran. As for its kings, called in Persian sources volât-e Hormuz, they were until then the vassals of the Persian monarch. But, with the arrival of Portuguese, they became subordinates to Portugal. This paper deals with some of the documents from National Archives of the Torre do Tombo that deal with interaction of the kingdom of Hormuz and the Portugese.