An early use of the name:
1817 William Crawshay, living in London, gained full control of Cyfarthfa Ironworks - his son William Crawshay (1788-1867) running the works was constantly at odds with his playboy brother Richard Crawshay, although operating as "Crawshay Brothers".
The formal company with this name was formed in 1879:
1879 On the death of Robert Thompson Crawshay, his son William Thompson Crawshay succeeded to the management of the extensive coalfields, and inherited his father's estate at Caversham in Berkshire and estate valued at under £1,200,000, and joint control of the business with his two brothers.
1879 Operating under the title Crawshay Brothers they reopened the Cyfarthfa Ironworks in October 1879 and proceeded to effect a changeover to steel production at Cyfarthfa. This move, however, did not prove to be an unqualified success and was insufficient to secure long-term survival of the works.
1902 Acquired by Guest, Keen, and Nettlefolds (GKN).
By 1910, the steelworks had been forced to close again
1915 Briefly reopened to produce materials for World War I
1919 The works closed for the last time. It fell into disrepair until it was dismantled in 1928. The failure of the works was a devastating blow to the local community, as it had depended heavily on the works for its economic livelihood.