The new mum continued: "Despite being delivered early, all three of us are fit and well and Freddie and I are now enjoying some quality time with our newly formed family.
Holly Branson has given birth to baby twins
"What's more, the little ones also arrived on mine and Freddie's third wedding anniversary - could there be a better way to mark the occasion?
"...Oh and lastly, if you were wondering about names… let us introduce you to Etta and Artie."
Sir Richard Branson didn’t waste any time in announcing that he has become a grandfather, and sharing his delight at the new arrivals on 20 December – the wedding anniversary that Holly and Fred share with Sir Richard and his wife Joan.
The multi-billionaire businessman tweeted his delight on Tuesday evening: "Magical day - @hollybranson & @freddieandrewes twins born on same date as their (& Joan & my) wedding anniversary!"
Holly and husband Fred have named ther new bundles of joy Etta and Artie
On his website the 64-year-old wrote: "Delighted to share the happiest of news - Holly and Freddie are now the proud parents of a beautiful baby boy - and a beautiful baby girl! Joan and I, along with Freddie’s parents William and Jill, are the proudest grandparents in the world.
"It turned into the most magical day," the proud new grandfather continued. "The twins were born on December 20th – the same date that Joan and I celebrate our wedding anniversary, and Holly and Freddie do too!
Holly, 32, announced she was pregnant with twins in August after marrying Fred in December 2011 on her father's private Necker Island.
The family, who usually spend Christmas on the island, enjoyed an early festive dinner at home this year due to Holly and Sam's impending arrivals. Sam Branson and his wife Isabella Calthorpe are also expecting their first child together in the next few weeks.