The President, Michael D Higgins, flies to London later for the first State visit to Britain.
President Higgins will be accompanied by his wife Sabina, while Tánaiste Eamon Gilmore will also travel as the official Government representative.
The visit is attracting increased attention after deputy first minister Martin McGuinness accepted an invitation to the State banquet with the Queen at Windsor Castle.
President Higgins will leave Aras an Uachtarán this afternoon when full military honours will be rendered and travel under escort to Baldonnel Airport.
He will fly to London before the historic visit officially gets underway tomorrow morning.
The schedule is packed over four days which is unusually long for an incoming state visit to the UK.
The detail and personal nature of the visit is deemed to represent the closer links between the two countries.
The first days of the visit will see events at Windsor and the Houses of Parliament, as well as a meeting with the British Prime Minister in Downing Street.
Other elements later in the week include a visit to a farm, events at the birthplace of Shakespeare, Oxford and Coventry.
Tánaiste Eamon Gilmore and his wife Carol Hanney will accompany the President and Sabina Higgins.