During the mid-1880s with the closure of the Llynfi Works and its associated collieries, the Maesteg district, with a population of about 10,000, faced an uncertain future. Fortunately, the local coal industry began to expand with the formation of North's Navigation Collieries Ltd in 1889. The colliery company was led by the remarkable Colonel North, the "Nitrate King" and, some years later, in 1900, another company led by Sir Alfred Jones of the Elder Dempster shipping line also developed collieries in the valley. Due to the expansion programme set in motion by the two mining companies, two of the local, former iron company collieries were modernised (Coegnant and Garth) and two new large collieries were sunk at Caerau and St John's (Cwmdu). With the development of the coal industry, the local population increased from about 10,000 in 1891 to almost 30,000 in 1921.