After the death of King Chulalongkorn in 1910, the relationship with his successor King Vajiravudh was less smooth. Prince Damrong finally resigned in 1915 from his post at the ministry, officially due to health problems, since otherwise the resignation would have looked like an affront against the absolute monarch.
During the brief reign of King Prajadhipok, the prince proposed that the king founded the Royal Institute, mainly to look after the National Library and the museums. He became the first President of the Royal Institute of Thailand. He was given the title Somdet Phra Chao Borommawong Thoe Krom Phraya Damrong Rajanubhab by King Prajadhipok in recognition to his works. This became the name by which he is generally known.
In the following years Damrong worked as a self-educated historian, as well as writing books on Thai literature, culture and arts. Out of his works grew the National Library, as well as the National Museum.
Being one of the main apologists of absolute monarchy, after the Siamese revolution of 1932 which introduced Constitutional monarchy in the kingdom, Damrong was exiled to Penang in British Malaysia. In 1942, after the old Establishment had substantially regained power from the 1932 reformists, he was allowed to return to Bangkok, where he died one year later.
Prince Damrong is credited as the father of Thai history, the education system, the health system (the Ministry of Health was originally a department of the Ministry of the Interior) and the provincial administration. He also had a major role in crafting Bangkok's anti-democratic state ideology of "Thainess".
On the centenary of his birth in 1962, he became the first Thai to be included in the UNESCO list of the world's most distinguished persons. On 28 November 2001, to honour the remarkable contributions the prince made to the country, the government declared that 1 December would thereafter be known as "Damrong Rajanupab Day".[6]
Royal Monument of HRH Prince Ditsawarakuman, Prince Damrong Rajanubhab
His many descendants use the Royal surname Disakul.