Sunandha Kumariratana was born on 10 November 1860 as the daughter of King Mongkut of Siam (Rama IV) and Princess Consort Piam. She was first Queen consort of King Chulalongkorn (Rama V) of Siam and also his half-sister. All of his four wives were also his half-sisters. King Mongkut had at least 82 children with various consorts and concubines.
Sunandha Kumariratana had a daughter on 12 August 1878, named Kannabhorn Bejaratana and she was pregnant again when tragedy struck on 31 May 1880.
While on the way to the summer palace at Bang Pa-In, the royal boat she and her daughter were travelling on capsized. They were many onlookers who witnessed the capsizing, but they were unable to help. They were forbidden from touching the Queen on pain of death, even if it meant that they couldn’t save her life. They were also instructed to do nothing by a guard on another boat, though he was later punished for his strict view of the law in such circumstances.
Her funeral procession was one of the most expensive in history. Queen Sunandha’s ashes were enshrined at the Sunandha Nusavarya Memorial in the Royal Cemetery at Wat Ratchabophit with her daughter. The grief-stricken King later erected a memorial to her and their unborn son at the Bang Pa-in Palace.