The progress of the Roman Catholic Church in Wales under a succession of able bishops between 1916 and 1962 was striking. The Church grew in strength, stature, and confidence. The expansion in the number of its adherents was largely due to continuing immigration from Ireland, England and the Continent. Although conversions from among the native population certainly occurred, they helped the Catholic cause only minimally. Furthermore, like the other Welsh denominations, the Church found itself in a constant struggle to retain its existing faithful. The growth of the Church in the Principality was one of the primary reasons why hostility and prejudice against Catholicism continued unabated down to the early 1960s. At a local level, the initial opposition to the re-emer gence of Catholicism was undramatic and soon subsided. In the wider sphere, however, animosity remained virulent. In denominational newspapers and conferences, ministers, clergymen and prominent laymen revealed deep anti-Catholic dispositions. Many reacted directly to the growth of the Church by warning fellow Welshmen of the insidious intentions of Rome and its Fascio-political threat. Others vehemently attacked Catholic belief and practice. The Catholic Church's unceasin g attempts to establish its own educational system in Wales became an ideal channel into which these prejudices were directed. While hostility remained fervent throughout the period, underlying_ it was the clear, yet gradual, acceptance of the Roman Catholic Church by the people of Wales. By 1962 the Church had achieved an accepted, and indeed revered, position among the Welsh denominations. The effect of increasing general tolerance, the wide-scale adoption of ecumenical ideals, and respect both for individual Catholics and for their promotion of social, moral and cultural issues, all helped transform the attitude of Welsh society towards the Church.