Thailand’s Queen Mother Sirikit, revered for her lifelong efforts to uplift the rural poor, preserve traditional crafts and protect the environment, passed away on Friday at the age of 93.

The Royal Household Bureau said the queen mother died at a hospital in Bangkok, where she had been receiving treatment for a blood infection since October 17. Despite intensive medical care, her condition did not improve.

Sirikit had been largely absent from public life in recent years due to deteriorating health. Her husband, the late King Bhumibol Adulyadej, died in October 2016.

Photos released by the palace on her 88th birthday showed her son, King Maha Vajiralongkorn, and other members of the royal family visiting her at Chulalongkorn Hospital, where she had been under long-term care.

Though often overshadowed by her husband and son, Queen Mother Sirikit was deeply admired and influential in her own right. Her portrait adorned homes, offices, and public spaces across Thailand, and her birthday—August 12—was observed nationwide as Mother’s Day.

Throughout her life, she spearheaded numerous royal development projects, from assisting Cambodian refugees to launching environmental conservation initiatives that saved large portions of Thailand’s forests.

However, as Thailand’s political climate grew increasingly turbulent in recent decades, her role also came under scrutiny. Stories circulated about her quiet influence during times of upheaval marked by two military coups and violent street protests. Her public appearance at the funeral of a protester killed in clashes with police was viewed by many as a rare political gesture.

Born Sirikit Kitiyakara on August 12, 1932, into an aristocratic family in Bangkok, she was related through both parents to earlier kings of the current Chakri dynasty—the same year that Thailand transitioned from absolute to constitutional monarchy.