The original Grosvenor Colliery was located near the Five Crosses area of the village, with possibly five pits sunk there by Richard, Earl of Grosvenor, in 1790. Pentre'r Fron Colliery, with 10 pits between Plas Mostyn and Heol Caradoc, was worked until 1819, when the mine was abandoned owing to flooding.
Several miners lost their lives in the incident, which was said to be caused by water coming in from the nearby Grosvenor Colliery. One local man, John Evans, was rescued alive from the pit, having been entombed for 14 days. He had survived by eating his tallow candles and sipping the drips of water from the pit roof.
The Coedpoeth Colliery, controlled originally by John Burton in 1823, was located between the turnpike road and the Talwrn Road. Examination of the 1872 Ordnance Survey map for the area shows many old coal shafts, giving evidence of the early 19th Century mining activity in the village.
Throughout the 19th and into the 20th Century, these early mining sites were redeveloped. The New Grosvenor Colliery (or 'Jockey Mine') was sunk in 1869 at Top Talwrn: it was owned originally by William Low, and later by J. Conyers Morrell, a Londoner, who lived at Roseneath in Wrexham. The mine depth was only 100 yards, and worked using single cages. It was also a very hot mine and was very badly ventilated.
By 1890 coal production there had ceased, and the mine was used only for the extraction of fireclay for brick making. The Coedpoeth Colliery reserves were also reworked during the century, with several large-scale plans for this colliery showing the workings of the Main, Brassey, and Crank coal seams between 1881 and 1919.
In the 1930s the New Talwrn Colliery Company further mined these reserves for house coal. This was a very small-scale operation, under the direction of G.W. Evans, Middle Road, Coedpoeth, and Thomas Owens, Talwrn Road. In 1938 the company employed just eight men, prospecting the old working, with production continuing until 1945.
Technological advances during the second half of the 19th Century certainly provided increased employment opportunities in the village. The number and percentage of men employed in the industry increased significantly. What was happening in Coedpoeth was also happening nationally across Wales. By 1913, at the height of the industry, a third of the male work force in Wales was involved in the coal industry.
The development of the mining industry in Coedpoeth did not only alter the landscape of the village, but it also changed the structure and organisation within the whole community. A new middle class began to emerge, with increased numbers of the village population being categorised as tradesmen.
The village also saw a huge increase in the number and range of professional people. Back in 1851 only six people would have fitted this description - four school mistresses, one male teacher and a police constable. In comparison by 1901 77 residents could be classed as professional, and included a physician, a dentist, a chemist, nurses, insurance agents, surveyors and magistrates' clerks.
The number of shopkeepers also rose significantly with a greater village population there were more families to provide for. In 1851 Coedpoeth had 15 shopkeepers and this increased to 59 by 1901, including 33 grocers and six butchers.
From 1850 onwards there was a huge influx of people into the village, for some the growth of industry brought with it increased wealth and social standing. However for many families life in an expanding mining community brought only increased hardship and poverty. What was certain was the rural monoglot Welsh community was gone forever.
