Thailand and Portugal released a joint issue to commemorate and 500th anniversary of Thai-Portuguese relations. In the reign of King Ramathibodi II of the Ayutthaya Period, Portugal was the first Western nation to come into contact with Thailand. There were trade transactions and co-operation in many areas. Thus, the relationships between Thailand and Portugal dates back almost five centuries to when the two countries established diplomatic ties on February 10th, 1859 by the signing of a trade and navigation agreement. In 1981, Thailand opened its first embassy in Lisbon whereas Portugal established its consular office in Bangkok in 1818.