In 1936 Dowlais played a part in the events leading to the abdication crisis of Edward VIII, when the King visited the steelworks and was reported as saying that "these works brought these men here.
Lewis brought to the partnership a complex system of leases that allowed the erection of a furnace and the right to mine iron ore, coal and limestone at Dowlais, Pantyrwayn and Tor-y-Fan.
[6] Under Guest's leadership, alongside his manager John Evans, the Dowlais Ironworks gained the reputation of being "one of the World's great industrial concerns".
[7] At its peak in 1845, the works operated 18 blast furnaces, employed 7,300 people and produced 88,400 tons of iron each year.
Lady Guest would be sole trustee while a widow but she remarried in 1855 and de facto control fell to Clark.
Though the Bessemer process was licensed in 1856, nine years of detailed planning and project management were needed before the first steel was produced.
To explain why there were no funds to invest, the manager made a new financial statement that was called a comparison balance sheet, which showed that the company was holding too much inventory.
Clark delegated day-to-day management to Menelaus, his trusteeship terminating in 1864 when ownership passed to Sir Ivor Guest.
However, Clark continued to direct policy, in particular, building a new plant at the docks at Cardiff and vetoing a joint-stock company.
[14] In 1912, King George V of the United Kingdom and Queen Mary made an official visit to the ironworks as part of a tour of south Wales.
[15] Unlike the Cyfarthfa Ironworks, the Dowlais Works' early conversion to steel production allowed it to survive into the 1930s.
On 18 November 1936 Dowlais Ironworks was visited by King Edward VIII, which at the time was closed, putting thousands out of work.