The body of Pauline Knowles-Samarraie was found after the fire
A man who married his ex-wife's daughter battered the older woman to death before setting her body on fire to cover his tracks, a court heard.
Mohammad Soboh, 41, of New England Road, Brighton, denies murdering Pauline Knowles-Samarraie, 72.
Lewes Crown Court was told her body was found in the bungalow she shared with him, his new wife Nada and their three children in Rottingdean in April.
The victim and defendant married for "convenience" in 1993, the jury heard.
He later married her daughter Nada and the whole family moved to Sussex.
'Unexplained fatal injuries'
The prosecution claimed Mr Soboh repeatedly struck Ms Knowles-Samarraie over the head with a blunt instrument and then set her body alight while his wife and children were out for the day.
The court heard a transcript of a 999 call made by Mr Soboh on 22 April in which he said he had found Knowles-Samarraie alight in the kitchen but was unable to reach her.
Alan Kent QC, prosecuting, said: "She was sitting with her back up against the patio doors with her head forwards and her arms up above her shoulders.
"The first firefighter who entered the kitchen noticed that her body was totally burnt from the waist upwards. From the waist downwards the fire was still burning on her thighs."
She was pronounced dead and Mr Soboh was treated in hospital for the effects of smoke inhalation.
Mr Kent said police were able to tell straight away that Ms Knowles-Samarraie had suffered "unexplained and extensive fatal head injuries".
Mr Soboh was arrested after being released from hospital and during a number of police interviews gave "an extremely full account" of his movements during the hours leading up to her death, according to Mr Kent.
He added: "What the Crown submits is this: the defendant was trying to suggest that her death might have been an accident caused by a fall and then by a fire because she was cooking in the kitchen.
"But alternatively, if it wasn't an accident, a stranger had been hanging around and the stranger had been given a piece of metal by the defendant."
Mr Kent said Ms Knowles-Samarraie had "lived an extremely interesting life" that was "marred by great personal difficulty and tragedy".
She met her first husband Munem, an Iraqi, in her hometown of Halifax, West Yorkshire, where he was studying A-levels.
He later become an oil minister under Saddam Hussein and was killed along with their son Paul.
The court heard Ms Knowles-Samarraie had a book published about her experiences under the Iraqi leader's dictatorship entitled, I Never Said Goodbye.
But he told the court she was a "secretive" woman who did not talk to her close friends about her "slightly unconventional" living arrangements.
He added: "She kept many things very private and there were very rarely visitors to their home.
"It may be the secretiveness or unwillingness to open up may have been a legacy from her time in Iraq, who knows."
The trial continues.