The Five Nations became Six with the arrival of Italy at the turn of the millennium and the competition has now witnessed 20 installments.
The birth of the Six Nations coincided with a transformation in Ireland's fortunes following a dismal 1990s and the oval ball game has grown enormously in popularity in the past two decades.
How well do you remember the first 20 years of the Six Nations? Take our quiz to find out.
Follow Ireland v Scotland (kick-off 4.45pm) on Saturday via our live blog on RTE.ie/Sport and the News Now app or listen live on RTÉ Radio 1's Saturday Sport. Highlights on Against the Head, Monday at 8pm on RTÉ2 and RTÉ Player.