Mundella's 1863 success in arbitrating the Nottingham industrial strife led to him being invited by many towns around the country to expound on the system of arbitration and to help settle a number of grave labour conflicts. Outbreaks of violence, including explosions and murders, in the Sheffield steel industry (known as the Sheffield Outrages) led to the 1867 Royal Commission on Trade Unions. Mundella showed the Commission that unions could play a positive part in industrial relations, and that working men could be trusted. In 1868 he was invited to address a joint meeting in Sheffield of the organised trades and the local branch of the Reform League. The leaders of his audience were so inspired by his speech that they assured him of their support if he were to stand for the Liberal Party in the Sheffield constituency in the forthcoming General Election.