Wales began their quest for a third successive Six Nations title with an unconvincing 23-15 win against Italy in Cardiff.
Ireland have a point to prove against Scotland in Dublin on Sunday after losing at Murrayfield last year.
New faces will add extra spark to an old rivalry as England travel to Paris on the opening weekend of the Six Nations.
Highlights from previous clashes between these two teams over the past six years.
Wales will begin their charge for an unprecedented third successive Six Nations title with an ideal first game, against Italy in Cardiff on Saturday.
The uncapped duo of Luther Burrell and Jack Nowell have been named in the starting XV for England's Six Nations opener against France in Paris on Saturday.
Stade Français flyhalf Jules Plisson will earn his first Test cap when he starts for France against England in Paris.
Keep an eye on these players during the European tournament, which kicks off this weekend.