The son of a powerful and wealthy Iron Master from Merthyr Tydfil, Henry Crawshay was the only iron king the Forest of Dean ever had. He was the owner of many local collieries, including Lightmoor. For the one hundred and ten years that Lightmoor worked, it belonged to the Crawshay family until it closed in 1940.

Henry Crawshay was proud of his family background and the fact that the Crawshays were Iron Masters. Perseverance, was their family motto and he must have been pleased to have had the mining rights of the Perseverance iron mine - one of the deepest pits in the Dean. It stood just besides the Crawshay's Shakemantle mines on the road between Ruspidge and Soudley and they also owned the nearby Buckshaft iron mines.

The last commercial mine in the Dean - Northern United - sunk in 1933, closed on Christmas Eve 1965, also belonged to the Crawshays before nationalisation.

The development of present day Cinderford came about largely through the need for dwellings to house the people who worked in the Crawshay works and mines. Workers came from many parts of Wales and England to seek employment in the iron and coal industries. The Crawshays built some large houses for their workforce, the best known being Rock House near St Johns Church, and The Villa, now demolished, at Ruspidge.

The major industry of the Crawshays was the Cinderford Iron Works which sprawled for much of the length of the valley at the bottom of the town. All that now remains of the vast Cinderford Ironworks are a few cinders spread around the Linear Park area. Other reminders of those days are the public house The Forge Hammer and the old tramways. The whole valley was lit up by the glow from the furnaces from 1795 until they were 'blown out' in 1894.

Henry Crawshay was one of the few 'Masters' to be a member of the established church. When in residence at Abbotswood House the Crawshays regularly worshipped at St Johns Church. This was considered to be the church of the Lightmoor Colliery because many of the miners from that pit worshipped there and were buried there.

The Crawshays lived at Abbotswood House in Ruspidge and also Oaklands Park near Newnham and also built Blaisdon Hall.