A mum suffocated her two young children and placed their bodies in the boot of her car, a court heard yesterday.
Fiona Donnison, 45, allegedly killed Harry, three, and two-year-old Elise after her relationship with their dad broke down.
She is accused of murdering them to hurt her ex
in the most extreme way possible. She then allegedly wrapped the youngsters in holdalls.
Jurors were told she had moved out of the family home six months earlier without telling Paul.
Christine Laing QC, prosecuting, said: "This is understandably a complex case particularly in relation to the motive.
"We say that responsibility lies not as a result of any mental illness but we say as a result of her personality."
She said Donnison, who was not married to Paul but had changed her name by deed poll, was a narcissist with an overdeveloped sense of self-importance and entitlement.
The couple, who had met in 1999 when both were married to other people, had a strained relationship, the court heard.
Donnison was also jealous and controlling of her partner and often exhibited highly manipulative behaviour, it was said.
She had enjoyed a successful career in financial services in the City, but was made redundant in July 2009.
It is alleged she moved out of the family home in Heathfield, East Sussex, with the children on September 1 after returning from a holiday to Ireland.
She had left a note saying "for the sake of the children I feel I have no choice but to move out... I'm sorry, Fiona".
Mrs Laing said the two children, described as "delightful, well-mannered and affectionate", were last seen alive on the afternoon of January 26 last year.
It is believed they were likely to have been killed sometime that evening.
Donnison denies two charges of murder.
