The President will meet the British Prime Minister David Cameron in London today, along with a visit to the University College Hospital.
He will also attend a youth event with Mayor Boris Johnson and a dinner at the Guild Hall.
Last night Michael D Higgins declared "the shadow of our past has become the shelter of our present".
And speaking at the State Banquet, Queen Elizabeth says no longer can we let our past ensnare our future.
The Queen added that her visit to Ireland had left a happy and enduring impression.
She says the Irish and British are becoming good and dependable neighbours, and better friends.
President Higgins says we have moved on from a past of trouble to one of mutual respect and close friendship.
Today he'll meet with British Prime Minister David Cameron, attend a youth event with Mayor Boris Johnson and attend a dinner at the Guild Hall.
