It was a bitter-sweet moment when David Cameron stood outside Number 10 in May, accompanied by his radiant and heavily pregnant wife Samantha, having secured his life's ambition.
As he savoured his triumph, the politician's thoughts cannot have far been from the one person in his family, who would never experience the sumptuous new lodgings - his son Ivan.
Sadly, the little boy was born with cerebral palsy and a severe form of epilepsy and died aged six in February 2009.
And now the leader is mourning another beloved figure in his life - his stockbroker father Ian, who died at 77, following a stroke during a break in France.
Click on photos for galleryMr Cameron made a last-minute dash to be with him in his final moments – after receiving a 6am phone call from his mother Mary.
Just before this year's general election, he told Sir Trevor McDonald how his father overcame disability to become a successful stockbroker.
"He's an amazingly brave man because he was born with no heels – quite a disability. "But the glass with him was half-full, normally with something alcoholic."
In childhood, Ian had endured several operations to correct the problem.
He cheerfully ignored his condition to live a full, successful and fun-loving life, including an education at Eton and a career within the family stockbroking firm.
Twenty years ago doctors were forced to amputate one of his troublesome legs. Then in 2006 he lost the other, as well as the sight of one eye.
What he didn't lose, said his son, was his "indomitable spirit".
Poignantly, Cameron senior did not get a chance to meet his new granddaughter Florence who was born unexpectedly early two weeks ago, while the British leader and his wife were on holiday.
Ian did, however, visit Downing Street and was able to see, what inspired by his example, his son had achieved.