Her official title was Preah Mohaksatreiyani Sisowath Monivong Kossamak Nearirath Serey Vathana (Khmer: ព្រះមហាក្សត្រិយានី ស៊ីសុវត្ថិ មុនីវង្ស កុសុមៈ នារីរ័ត្ន សេរីវឌ្ឍនា, Preăh Môhaksâtrĕyéani Sĕisŏvôtth Mŭnivôngs Kŏsâmeă Néariroătn Sérivôdthônéa).

After the coup in March 1970, Kossamak was placed under arrest, but retained her title before being stripped of all status during the formal proclamation of the republic in October of the same year.

[3] A notable state visit was that of Chen Yi in November 1958, who led a women's delegation from the People's Republic of China.

[3] When king Norodom Suramarit died in 1960, a demonstration took place in Battambang in which the protestors called for the widowed Queen Kossamak to take the throne as a ruling monarch.

[3] However, Prince Sihanouk refused to agree to the suggestion because of his uneasy relationship with his mother and his unwillingness to allow anyone but himself as head of state.

In 1960, King Suramarit died and Sihanouk became Head of State, with his mother, Queen Kossamak performing as the ceremonial monarch.

Her prestigious public role was described in the New Cambodge 5 (September 1970): The growing opposition against the Sihanouk regime, however, did influence the perception of the queen mother as well.

that Queen Kossamak did exercise the prerogative in influencing appointments to civil service positions and investment in non-transparent enterprises, which were normal for the Cambodian elite at the time.

[3] Pictures of Queen Kossamak, a non-ruling monarch but a symbol of royal permanence, were stripped from government buildings.