1520: King Manuel I creates the public mail service of Portugal, the Correio Público—Public Post Office.
1533: the first postal service regulation in Portugal.
1753: the first financial mails regulations in Portugal.
1821: the beginning of house-to-house mail delivering in Portugal.
1880: the fusion of the Post Office and the Telegraphs Department in one single service, the Department of Posts, Telegraphs and Lighthouses—Direcção-Geral de Correios, Telégraphos e Faróis.
1911: the department received administrative and financial autonomy from the Portuguese State and become the General Administration of Posts, Telegraphs and Telephones—Administração-Geral dos Correios, Telégrafos e Telefones—adopting the CTT acronym which was kept until today, even after the several changes of official name.
1953: CTT adopts the horse rider logo. The logo represents an ancient postman rider of the CTT, announcing his arrival with a bugle. The logo was reformed three times, the last one in 2004.
1969: CTT becomes a State Company, adopting the name CTT Correios e Telecomunicações de Portugal—CTT Posts and Telecommunications of Portugal.
1992: the telecommunications service is separated from the CTT, becoming an autonomous company. At the same time, CTT become a public limited company (with all shares owned by the Portuguese government), adopting the name CTT Correios de Portugal—CTT Posts of Portugal.