John Davies was born on 24 October 1784 in Llanwrthwl parish, north Breconshire, into a poor family, his father scraping a living as a labourer. Little is known of his early life save that he received very little schooling and at some time he left his isolated rural area for Swansea.
From Swansea he went to sea for several years, during which time he learned to read and write, self-educating himself in English, Welsh, a wide range of knowledge, and in book-keeping skills that were to give him plenty of employment later in Tredegar. His father had died during his time at sea and in the meantime, his mother and brothers had moved to Tredegar.
He was an inveterate diary keeper and some of his diaries have survived. They are written almost wholly in Welsh, and can be read in the Cardiff Central Library. Unfortunately, the surviving diaries do not cover the first twenty five years of his life in the town. Nor are the four volumes which do exist continuous as there are gaps for some years, but they do span from 1831, by which time he was already into middle age, to the January prior to the June of 1864 when he died. Nevertheless, they amount to over two hundred pages of handwritten entries from a time when Tredegar was very much growing and prospering.