The United Kingdom Royal Commission on Railway Gauges was held in 1845 to choose between the broad gauge of the Great Western Railway and its associated companies and the so-called narrow gauge (now known as standard gauge) of that had been installed in most of the rest of the country. The situation in Ireland, where there were three gauges, was also considered.
The members of the commission were: J. M. F. Smith, G. B. Airy, and P. Barlow. John Fox Burgoyne gave evidence to the commission on the desirability of standardising the British railway gauge to assist with the movement of troops in the event of invasion. The commission in its final report, while recognising that broad gauge was technically superior, nevertheless recommended its abolition as the cost and difficulty of converting the majority of railways, which were narrow gauge, was too great.
Following the royal commission, the Railway Regulation (Gauge) Act 1846 (9 & 10 Vict. c. 57) was passed, which mandated all new railways to be constructed to in England, Scotland and Wales, and in Ireland. The Great Western Railway was allowed to continue with its broad gauge.
Unlike Italy and France, which regulated the choice of narrow gauges, Britain did not, resulting in a large number of alternatives, including: