Nonconformity was a major religious movement in Wales from the 18th to the 20th centuries. The Welsh Methodist revival of the 18th century was one of the most significant religious and social movements in the modern history of Wales. The revival began within the Church of England in Wales, partly as a reaction to the neglect generally felt in Wales at the hands of absentee bishops and clergy. For two generations from the 1730s onwards the main Methodist leaders such as Howell Harris, Daniel Rowland and William Williams Pantycelyn remained within the Church of England, but the Welsh revival differed from the Methodist revival in England in that its theology was Calvinist rather than Arminian. Methodists in Wales gradually built up their own networks, structures, and meeting houses (or chapels), which led, at the instigation of Thomas Charles, to the secession of 1811 and the formal establishment of the Calvinistic Methodist Presbyterian Church of Wales in 1823. The 18th-century revival also influenced the older nonconformist churches, or dissenters – the Baptists and the Congregationalists – who in turn also experienced growth and renewal. As a result, by the middle of the 19th century, Wales was predominantly a nonconformist country. 19th century Starting in rural areas and small market towns, the 19th century was the golden age of Welsh nonconformity. Some small settlements, such as Carmel, Nebo and Sardi, grew around a chapel or meeting house and were named after it. Some of these settlements, such as Bethesda, Gwynedd, became large settlements. In the era of rapid industrialisation after the Napoleonic Wars, nonconformity became firmly established in the new industrial settlements of South Wales as migrants from the rural counties brought their religious affiliations with them. In places such as Merthyr Tydfil, Aberdare, Llanelli and Neath, Nonconformity grew alongside industry and by the 1880s these towns were regarded as "citadels of dissent", with their ministers and deacons having a powerful role among a new middle class elite which dominated public life. The ministers also had considerable influence within working class networks which, in part, reflected their own social origins. The Religious Census of 1851 showed that 80% of those who attended a place of worship on Census Sunday in Wales were Nonconformists, even though the large proportion of the population, even in Wales, who were not recorded in the census, suggested that the influence of religion within society was far more