Born at Haslingden, Lancashire, England, he was brought by his father (British entrepreneur William Cockerill) to the Liège region, where he continued the family tradition of building wool-processing machinery.

[3] After the victory over Napoleon at the Battle of Waterloo in 1815, the Prussian Minister of Finance, Peter Beuth, invited the Cockerill brothers to set up a woollens factory in Berlin.

[9] By 1840, the plant had sixteen steam engines producing total power 900 hp (670 kW) in continual work and employed 3000 persons.

[10] After the Belgian Revolution of 1830, the new Kingdom of Belgium claimed the property of William I,[8] and in 1835, John Cockerill made himself the sole owner of the works.

[2] In 1838/9, military tensions between Belgium and the Netherlands caused a rush on the banks for hard currency; as a result of the crisis, John Cockerill's company became bankrupt.