An inquest opening at Wakefield Coroner's Court heard 62-year-old Diane Jones, of Ambleside Road, Fryston, Castleford, was assaulted on March 14 and died from her injuries in a Leeds hospital a week later.
Senior coroner Kevin McLoughlin said: "Diane Jones was the victim of a serious assault with a hammer and she was admitted to hospital.
"But despite surgical treatment she deteriorated to the point where a decision was made to withdraw active treatment and she died at 8.23pm on March 21 at Leeds General Infirmary."
the inquest opening was told that a provisional post mortem report by consultant forensic pathologist Dr Kirsten Hope found the cause of death was a head injury.
The court was told Mrs Jones was born in Ferrybridge and that her maiden name was Cook.
Mr McLoughlin adjourned the inquest pending the outcome of police enquiries.
West Yorkshire Police launched a murder enquiry after Mrs Jones' death.
Police said after the inquest opening that a 42-year-old man, who was arrested at the time in connection with the incident, remains in police custody and enquiries remain ongoing.
Police said they were called out to a house on Ambleside Road in Fryston just after 8.30pm on Wednesday March 14 following a report that two people had been seriously injured.
Diane Jones and a 59-year-old man were taken to hospital for urgent medical treatment.
The 59-year-old man is recovering from his injuries.
Floral tributes to Mrs Jones have been placed outside the now boarded-up house on Ambleside Road.
One neighbour, who did not want to be named, spoke of the shock at finding out about her death.
He said: “She was a really nice lady and had been living there a long time. We didn’t really see a lot of her, just now and again because she had been poorly.
“We were all really shocked to find out what had happened.”