The firm of Samuel Walker & Co, Rotherham, Yorkshire, was founded in 1746 by the brothers Samuel, Aaron and Jonathan Walker. From about 1780 they supplied many iron guns to the Board of Ordnance these being with few exceptions of excellent quality. The company's mark was W Co on the left trunnion. In 1809 the head of the firm was Joshua Walker. The firm was wound up in 1817. Then about 1820 Samuel Walker, grandson of Samuel Walker above in association with William Yates took over the Gospel Oak Ironworks at Tipton, Staffordshire and in 1822 commenced producing guns using machinery brought from the original Walker foundry at Rotherham. The firm which was in existence until circa 1860, used the same W Co mark on its guns as had the earlier Walker firm.