Gerolamo Emilio Gerini (Thai: พระสารสาสน์พลขันธ์, RTGS: Phra Sarasat Phonlakhan) was born in Cisano sul Neva, Province of Savona, Kingdom of Sardinia on March 1, 1860.

In 1883 he left the Army to serve as the secretary of the minister of the northern division, Maha Mala, uncle of Rama V, King Chulalongkorn, in such assignment he travels and visits most of the Country, acquiring a perfect mastery of Thai language and also of other local languages, such as Malay, Burmese, Mon, Khmer and many local dialects.

In 1887 he backed to the Siamese Army, with the degree of Major and the title of Luang and the position of General Director of Military Education.

With two other scholars (Oskar Frankfurter and A. Cecil Carter) in 1904, under the High Patronage of Prince Vajiravudh (later King Rama VI) he was a driving force to establish the Siam Society, to promote knowledge of the culture of Thailand and its surrounding region, still today very active and probably the most important institution in its field.

Back in Europe he was often appointed by the Siamese Court and the King Rama V, who trusted and prized him, for official diplomatic and military missions and to represent Siam in Orientalists’ and Archaeologists’ Conferences.