He was educated at Lincoln College, Oxford, and began preaching with the Presbyterian Church of Wales in 1856.
At present, the Presbyterian Church of Wales has around 30,000 members who worship in around 700 churches.
Between 1811 and 1823, the Welsh Calvinist Methodists would become the Presbyterian Church of Wales.
Mawphlang was the centre of Presbyterian Church of Wales missionary and medical activity in the Khasi Hills during the 1890s.
In 1957, he was Moderator of the General Assembly of the Presbyterian Church of Wales.
In 1932, he was prominent in the discussions of the Presbyterian Church of Wales on formulating a parliamentary bill relating to the church.
In August 1937, Hughes applied to become a missionary for the Presbyterian Church of Wales.
The Presbyterian Church of Wales draws up a confession of faith and becomes a separate body.
He became moderator of the Presbyterian Church of Wales.
He was effectively the founder of the Presbyterian Church of Wales, also known as the Calvinistic Methodist church.