A father was the "prime mover and dominant player" in scheme to start a blaze which killed his six children as part of a plan to frame his ex-girlfriend after becoming locked in a custody battle with her, a court heard.
Mick Philpott is accused of hatching the scheme to set up his former mistress and diminish her chances of winning an upcoming residency court hearing involving their children.
Jurors at Nottingham Crown Court, where he and his wife Mairead are on trial for the manslaughter of the youngsters, heard that Philpott was livid when Lisa Willis left him three months before the blaze.
He could simply not accept that she had gone and embarked upon a plan to set her up and point the finger of blame at her for setting fire to the family home in Victory Road in Allenton, Derby, it is claimed.
Richard Latham QC told the jury: "Michael Philpott, it won't surprise you to know, was the prime mover and dominant player in this unlawful and highly dangerous enterprise that, in the end, went so horribly wrong."
Part of his motivation may also have been to get a bigger home for the family, which in turn may have persuaded Ms Willis to come back, the court heard.
"He wanted better accommodation from Derby Homes, the fire was a way of achieving that end. This was a three bedroom house, he wanted all 11 children to continue living with him," Mr Latham added.
Philpott denies six counts of manslaughter in relation to the deaths. His 31-year-old wife and a third defendant, 46-year-old Paul Mosley, also deny the same six charges.
Mick and Mairead Philpott's children - Jade, 10, and her brothers John, nine, Jack, eight, Jesse, six, Jayden, five, and Duwayne, 13 - all perished after the fire which engulfed their home as they slept in their beds upstairs in the early hours of May 11 last year.
A total of 11 children also lived there until February - six were those of Mick and Mairead Philpott, while four were his children with Ms Willis. Another child was Ms Willis's with another man.