Natanaree PosrithongMahidol University. International College. Social Science Division2015-08-202018-04-052015-08-202018-04-0520152010Silpakorn University International Journal. Vol. 9, No. 10 (2009-2010), 87-115https://repository.li.mahidol.ac.th/handle/20.500.14594/10484Objective: This research has four main objectives as follow:(i) To explore the origin of the Russo-Siamese relations.(ii) To examine the impact of the Russo-Siamese diplomatic relationship on the Franco-Siamese territorial conflict.(iii) To discover the lasting legacy of the relationship in the process of modernisation of King Chulalongkorn’s reign. Methods:(i) Data Collection (ii) Textual Analysis of the primary records (iii) Literature Survey Results:(i) The foundation of the great Russo-Siamese relationship is unique in its nature based on all three origins; the Czarevitch’s visit to Siam, the King Chulalongkorn’s visit to Russia, and finally the other personal relationships between the Siamese and Tsar Nicholas II. (ii) As a result of the firm establishment of the Royal friendship, Russia was acting as a mediator in the Franco-Siamese conflict.(iii) The modern process of Siamification is a direct heritage of the Siamese-Russo relations.Conclusion:(i) Even though the Russian did not resolve the Siamese problem due to its many limitations, its alliance was essential to the position of Siam in an international arena.(ii) The Siamification was a successful program unlike the Russification.engMahidol UniversityImperial friendshipTerritorial conflictsRussificationSiamificationArticleSilpakorn University