In the 1940s hydromtallurgy benefitted a great deal from Manhattan Project in USA, then in the 1950s a new technology was introduced by Sherritt-Gordon Mines in association with the Mines Branch in Ottawa to treat ores with ammonia under pressure and to precipitate metals from solution by hydrogen under pressure. Since then hydrometallurgy has made great progress as evidenced by the number of conferences held to discuss this topic. A personal view of these developments with those involved is given.