Political Relations

Thailand and the United Kingdom enjoy longstanding ties of over 400 years. The English East India Company first arrived in Siam in 1612, during the reign of King Songtham of Ayutthaya and King James I.

Diplomatic relations between Thailand and the United Kingdom were established in 1855, as a result of the Treaty of Amity and Commerce between the British Empire and the Kingdom of Siam. The said Treaty, also known as the Bowring Treaty, was signed in Bangkok on 18 April 1855, during the reign of King Mongkut (King Rama IV) and Queen Victoria.

The United Kingdom established a consulate in Siam in 1856. The following year, on 19 November 1857, Phraya Montri Suriyawong, considered Thailand’s first ambassador to the United Kingdom, was granted an audience by Queen Victoria at Windsor Castle to present a letter and gifts from King Mongkut to the Queen. The Siamese Legation in London was established in 1882, with M.C. Prisdang Jumsai serving as ambassador.

Bilateral relations between the two countries have been close and cordial since then, with cooperation expanding in all dimensions. There have also been regular exchanges of visits between the two sides at all levels, including that of the royal families.

At present, the ‘Thailand-United Kingdom Strategic Dialogue’ serves as the main high-level forum for regular consultations between the two sides on areas of bilateral collaboration as well as on regional and global issues of mutual interest. Meeting at the level of Vice Minister of Foreign Affairs, the inaugural session of the Strategic Dialogue took place on 20 May 2013 in Bangkok. The most recent meeting--the Fourth Strategic Dialogue--was held on 30 June 2022, co-chaired by UK Minister for Asia Amanda Milling and Thai Vice Minister for Foreign Affairs Vijavat Isarabhakdi. The Thai-United Kingdom Parliamentary Friendship Group has also been set up as a mechanism to promote parliamentary ties.

Thailand and the United Kingdom have developed close defence and security ties, with cooperation covering wide-ranging areas including defence procurement, military education and training. Both sides have worked together on traditional and maritime security as well as non-traditional security, such as cyber security and humanitarian assistance. The two sides also conduct joint military exercises called 'Panther Gold’ as well as take part in 'Cobra Gold.' The latter is the largest multi-national military exercise in the region held annually in Thailand. In 2022, both sides signed a Memorandum of Understanding on Defence Cooperation, which serves as an important framework for further joint exercises, regular bilateral talks and sharing best practice.

Thailand and the United Kingdom also work closely together at the regional and international levels. Thailand supports the United Kingdom, as ASEAN’s latest Dialogue Partner, in its increasing engagement with South East Asia and the region at large. The two countries also work closely with each other at the United Nations as well as other multilateral organisations and fora.

As for latest developments, Thailand and the UK's bilateral relations have been elevated to that of a strategic partnership. In March 2024, H.E. Mr. Parnpree Bahiddha-Nukara, then the Deputy Prime Minister and Minister of Foreign Affairs of Thailand, and the Right Honourable Lord Cameron of Chipping Norton, then the Secretary of State for Foreign, Commonwealth, and Development Affairs of the United Kingdom, signed the UK–Thailand Strategic Partnership Roadmap during the latter’s visit to Thailand.

The partnership aims to strengthen the relationship of the two countries at bilateral, regional and multilateral levels in all areas including political, security, trade and investment, agriculture, climate and energy, science and technology, health and people-to-people links. This strategic partnership marks a significant milestone in the two countries’ bilateral ties, as they will celebrate the 170^th anniversary of their diplomatic ties in 2025.