Nebo was established in the early 19th century, when the Hirwaun ironworks were in operation At that time a number of members of the Independents, the Calvinistic Methodists and the Baptists lived in the village of Hirwaun. For communion they went to Aberdare, but they came together for prayer meetings at houses in Hirwaun. The Independents were generally members of
Ebenezer, Trecynon. In 1823, a small chapel was built which was called Nebo, or Pennebo. This was used until 1830, when, following a revival which drew many additional members and listeners, a larger chapel was required. This was used for several years without formal seating or adornments. Eventually, in 1836, this was rectified. The minister from 1823 until 1835 was Joseph Harrison of
Ebenezer, Trecynon, but when his ministry at Ebenezer came to an end so did his connection with Nebo. In early 1836, John Davies of
Llantrisant became minister at both Ebenezer and Nebo, and he remained until 1840, when he moved to Mynyddbach, near Swansea. Thereafter, Ebenezer and Nebo had separate ministers. ==The pastorate of William Williams 1841–77==