text: Liddle was born near Sunderland, in the North East of England, in 1974. In 1997 he graduated with a BSc(Hons) in chemistry with applied chemistry from Newcastle University. His degree included a year working as a research scientist for ICI Performance Chemicals at Wilton, Teesside. Alongside a stint in the Territorial Army, Liddle continued his studies at the university and received his PhD in 2000. His PhD supervisor was Professor W. Clegg.