It is timely to pause as we reach the centenary of the creation of the contested border which divides Ireland and the advent of Brexit to examine teacher education across the island, revealing intersecting contrasts and similarities which reflect both common origins and increasing divergences. The relatively high esteem of both scholarship and of the teaching profession embraces important common strengths -- the student's lamp shines brightly across the island, a full century after Yeats penned the words in the title of this article. Recent reviews of teacher education provision on each side of the border, conducted by overlapping international panels, have produced quite similar recommendations but markedly contrasting outcomes. The article concludes by contrasting the recent trajectories of policy and practice for the teaching profession across the island and identifying key challenges for the next century.