They won 40-10 against Scotland at Murrayfield, and then saw their place at the top of the table confirmed after England failed to beat France by the required points margin.
The Taoiseach Enda Kenny has sent his congratulations to the Irish team and staff involved saying the “flair shown by the Irish team was a sight to behold”.
While Minister of State for Sport, Michel Ring has also congratulated the Irish side after they retained the trophy.
