As a trainee history teacher I cannot believe that a modern liberal society can contemplate deliberately making history a means to create nationalistic fervour. Students should be given the opportunity to learn about as wide a spectrum of societies as possible, not encouraged to become insular and bigoted by the excessive priority given to the past of the country in which they happen to live.
All students should learn about the important events in the world's collective past (in Europe this would presumably include world wars, Holocaust and colonialism). It should be recalled what sort of mindsets have resulted from past leaders' insistence upon ever-increasing emphasis on their own nation state, within school teaching.
The phrase, "not just translated from the English", seems to indicate an attempt to use a distorted history, as a part of "every subject", to further exacerbate the animosity that can be felt in Welsh nationalist regions.
Even if these nationalists believe they are achieving something worthwhile, those with control over the curriculum will resist these moves: schools must not become a breeding ground for racism and hatred.
107 Mary Vale Road