The postal history of Portuguese India goes back to the earlier days of the colony. The postal history begins with communication between the Viceroy and the Court at Lisbon soon after the conquest of Old Goa by Afonso de Albuquerque in 1510. Letters, written in triplicate, were carried by separate ships because of the hazards of the voyage. Mail was carried by an overland route, as well. The early communications of Portuguese India had an official character and the correspondence is now to be found in museums and governmental and ecclesiastical archives. Early mails Regular mail is known to have been exchanged with Lisbon from 1825 on. Portuguese Indian postmarks are known from 1854, when a post office opened in Goa and an extraterritorial British East India Company post office opened in Damaun. A Portuguese Indian post office opened at Diu, also, in 1880. The British East India Company post office in Damaun, selling British Indian stamps, was maintained between 1854 and November, 1883. The Damaun cancellation showed "13" within downward sloping diagonal bars, a "used abroad" Renouf "Type 4" cancellation. British India postage stamps were also available at the Portuguese post office at Goa from 1854 until 1877. Before the Universal Postal Union was established in 1874, a country had to conclude a separate postal treaty with each other country with which it transacted international mail. Portugal had a postal convention with Great Britain, so mail was routed through Bombay and carried on British packets. First stamps The first postage stamps of Portuguese India were issued 1 October 1871. These were issued for local use within the colony. Stamps of British India were required for overseas mail. The design of these first stamps simply consisted of a denomination in the center, with an oval band containing the inscriptions "SERVIÇO POSTAL" and "INDIA PORT.". The dies were recut several times and printed on several kinds of paper, resulting in an extremely complicated situation that has been intensively studied; about 55 types have been identified as appearing between 1871 and 1877, some of which are quite rare. Regular issues In 1877, Portugal included India in its standard "crown" issue, with nine values ranging from 5r to 300r. These stamps ran out in 1881 and the old local stamps were surcharged with various values, resulting in nearly 100 distinct types. Additional "crown" stamps arrived in 1882, but in the following year were