Clark, 34, of Wilmslow, Cheshire, smothered 11-week-old Christopher in December 1996 and killed Harry aged only eight weeks by smothering or shaking him in January last year. Both babies died in the bedroom of her pounds 250,000 luxury home.
Her third child, a boy aged one, has been taken into care.
Jailing Clark at Chester Crown Court, Mr Justice Harrison said he had received a full psychiatric report of 50 pages which he had considered carefully. "It highlights your history of alcohol abuse from at least 1996 onwards. I stress, however, there is no evidence you had consumed any alcohol on either occasion. You killed your babies nevertheless," he said. "The plain fact of the matter is you have taken the lives of two vulnerable and defenceless babies. The enormity of the seriousness of what you did is self-apparent and can't be over-emphasised."
A jury of seven men and five women took eight hours to return guilty verdicts on the two murder charges against the corporate lawyer earlier this month. But Mr Justice Harrison postponed sentence until today to allow more investigation into the case's background.
Mr Kelsey-Fry, for the defendant, said he was bound by his instructions and could offer no explanation or mitigation for the crimes. However, he noted that such an act "could only result from a soul tortured in a way we cannot understand."
He also stressed that "however abhorrent the convictions may be, Clark did not represent a danger to the public."
The jury heard during the trial that both Clark's babies had shown signs of previous physical abuse, including brain damage and broken ribs. It was also told that the policeman's daughter from Devizes, Wiltshire, had been fearful that motherhood would steal her looks and figure.
But the jurors were unaware until after the trial that Clark was a depressed alcoholic who had received counselling for her drink problem.
Her husband, Stephen, a partner at Addleshaw Booth and Co, where she worked, has stuck by his wife throughout.
Defence lawyers say they intend to appeal.Reuse content