Archie Battersbee died from a "catastrophic" brain injury, an inquest into the 12-year-old's death has heard.
The boy from Southend, Essex, died on August 6 following a long life support battle.
He had been in a coma since he was found unconscious in April and was being kept alive by a combination of medical interventions, including ventilation and drug treatments.
Parents Hollie Dance and Paul Battersbee had fought a long-running legal fight over the withdrawal of treatment, making bids to the High Court, Court of Appeal and European Court of Human Rights to have him transferred to a hospice to die.
An inquest into his death opened this morning, EssexLive reports, with a date for a full hearing set for next year.
Coroner's officer Paul Donaghy said Archie was found unresponsive in his home on April 7.
He said: "Paramedics attended and they reported a Glasgow Coma Scale of only 3 and confirmed a cardiac arrest. CPR continued and Archie was transported to Southend Hospital.
"Archie was thereafter transferred to the Royal London Hospital and Great Ormand Street Hospital who were both in agreement that surgical intervention would not help Archie. He was reviewed by the Paediatric Neurology team during his admission.
"Second opinions were also provided by multiple professionals from the Royal London, Queen's and Great Ormond Street Hospitals who agreed that Archie had suffered severe irreversible brain injury.
"The High Court, Court of Appeal and Supreme Court were involved in applications to determine the direction of care and the best interests of Archie.
"With the authority of final court order, life-sustaining treatment was withdrawn on August 6, 2022, in a side room on the intensive care unit and Archie died surrounded by his family and friends.
"Death confirmed by a hospital consultant."
Mr Donaghy said a provisional cause of death was identified as catastrophic hypoxic-ischemic brain injury secondary to strangulation.
Senior Coroner for Essex Lincoln Brookes set a date for the full inquest into Archie's death for February 7 next year. He told the court that an inquest would be to learn who died, and where, when, and how they came about their death, with "no one being on trial" during an inquest.
He added: "I also want to take the opportunity to say that Archie's death is a tragedy that so many people, especially his family on a personal level.
"I would like to extend my deepest condolences [to Archie's family] on behalf of myself and my officers."
