Easter and the Heritage of St. Ronan

Why do we celebrate Easter at the time we do? Thank St. Ronan of Iona. According to the Catholic Encyclopedia:

St. Ronan of Iona is explicitly referred to by St. Bede as one of the protagonists of the Roman custom of celebrating Easter as against the Irish tradition, and he had a warm controversy on the subject with his countryman St. Finan, Bishop of Lindisfarne, 660. This controversy was ended at the Synod of Whitby, in 664, when St. Ronan's views were upheld.

The Venerable Bede records that St. Wilfrid asked those at the Synod of Whitby (including Saints Colman and Chad of Lichfield) in 663/4 A.D.:

You certainly sin if, having heard the decree of the apostolic see, and of the universal Church, and that the same is confirmed by Holy Writ, you refuse to follow them; for, though your fathers were holy, do you think that their small number, in a corner of the remotest island, is to be preferred before the universal Church of Christ throughout the world?

Thus did Easter's dating become the heritage of St. Ronan.