George is best remembered for his 0-4-2 and 0-6-0 tank engines; these were long-lived, and even when life-expired they were replaced by Collett and Hawksworth with remarkably similar locomotives, the well-known 1400, 5700 and 1600 classes.
It was presumably in 1824 that the family took up residence near Newcastle at Newburn-on-Tyne, a few miles from George Stephenson's birthplace and at that time at the centre of avant-garde steam locomotive engineering.
At the age of 14 he started work at nearby Walbottle Colliery, which at that time was a horse waggonway with stationary engines to haul trains up the inclines.
At that time British engineering know-how was much in demand on the Continent, and from Brighton George crossed the Channel in order to work for a period on the Northern Railway (Nord) of France.
Wolverhampton's task at first was to keep the miscellaneous stock of the various standard gauge lines in working order, but from 1858 Joseph Armstrong was ready to start constructing new locomotives there.
Because the Great Western now had in effect two independent locomotive works, the scene was set for a difficult personal situation, George Armstrong and William Dean being de facto rivals for the post of Joseph's assistant at Swindon.
It was with this delicate situation in mind that Joseph decided to continue to give his brother a largely free hand not only in the design of Wolverhampton's locomotives, but even the way they were painted.
George Armstrong's rugged northern character made itself felt - "he didn't give a damn for any man and was taking orders from none.
[12] One of George's responsibilities was to oversee the running of the royal train as far as the junction with the London and North Western Railway at Bushbury, when Victoria was travelling to or from Scotland; a duty that he undertook more than 120 times.