[1] Born as Phra Ong Chao Tisavarakumara (พระองค์เจ้าดิศวรกุมาร; "Prince Tisavarakumarn"), a son of King Mongkut with Consort Chum (เจ้าจอมมารดาชุ่ม; Chao Chom Manda Chum), a lesser royal wife; he initially learned Thai and Pali from private tutors, and English at the Royal School with Mr. Francis George Patterson.

Many minor provinces were merged into larger ones, the provincial governors lost most of their autonomy when the post was converted into one appointed and salaried by the ministry, and a new administrative division—the monthon (circle) covering several provinces—was created.

[3] Nor aware that the Bowring Treaty, which nearly all considered a significant advancement, had accomplished none of its objectives and had been set-back for the Siamese for the ensuing decades.

In December 1891, during a lunch hosted by the British ambassador to Egypt, Damrong met Gustave Rolin-Jaequemyns, who had edited the first issue of Revue de Droit International et de Législation Comparée ("Review of International Law and Comparative Legislation"), which had appeared late-1868 with contributions from many noted scholars.

[8] The King had been impressed by the way Damrong organized the re-equipment of Thai artillery in his military capacity and how he successfully managed three schools and then the education ministry.

[16][17] Damrong's most important reform, however, was the creation of the thesaphiban system by which the provincial administration was professionalized and made responsible to and dependent on the central government.

The system was named after the thesaphiban or superintendent commissioners who exercised authority over in which groups of provinces called monthon or circles.

[19] Damrong and the thesaphiban also attacked the independence of provincial nobility by taking over their sources of revenue, such as judicial fees and transit duties, then using some of this money to pay them salaries.

[20] Damrong and his ministry also sought to appoint Interior officials to run districts (the administrative division below provinces) and to have locally elected elders take responsibility for keeping the peace and collect taxes at the commune and village levels.

[21] These changes were formalized countrywide in the Ministry of Interior regulations of 1899, turning provincial governors from semi-independent nobles to officials of the central government.

He was given the title Somdet Phra Chao Borommawong Thoe Krom Phraya Damrong Rajanubhab by King Prajadhipok in recognition to his work.

On 28 November 2001, to honour the contributions the prince made to the country, the government declared that 1 December would thereafter be known as "Damrong Rajanupab Day".