Leonard Rotherham was born in Sutton-in-Ashfield, near Nottingham, on 31 August 1913 and his early life went through difficult times. His father, Bernard Rotherham, who left school at the age of 13, first became a coalminer, and later started a small haulage business with two lorries and a bus with solid tyres. The business prospered for a while but was sold up during the recession and his father returned to coal mining at the Welbeck colliery. Leonard's mother, Jane Rotherham, died when he was 10 years old; his father felt unable to look after his son and sent him to live with an aunt, Mrs Rhoda Page, who also had four sons of her own. By all accounts, Mrs Page was an inspirational woman, although the family lived on a poor farm with very little money. However, Leonard went to the Crich Church of England primary school, where he attracted the interest and support of the headmaster, a Mr Haywood; this marked a turning point for him. From this school Leonard won a scholarship to The Herbert Strutt School in Belper, Derbyshire. This school was founded in the name of a famous family, for Jedediah Strutt was once a partner of Richard Arkwright's; together they established the first cotton mill in Nottingham. At this school he met Nora Mary Thompson, whom he would marry in 1937. From here he won a scholarship from the Nottingham branch of the newly formed Mineworkers Union, a Derby County Major Scholarship, as well as a State Scholarship. With this combined support, he gained a place at University College London, where, in 1934, he obtained a first-class honours degree in physics with subsidiary mathematics. A year later he received an MSc from the same institution for research on the viscosity of liquids performed under the supervision of Professor E.N. da C. Andrade (FRS 1935). Following his decision to undertake research in industry, Rotherham joined the large steelmaking company Firth–Brown in Sheffield in 1935. He was appointed as a physicist in the research department under the direction of Dr William H. Hatfield (FRS 1935), who was Head of the Brown–Firth Research Laboratories. Their name was peculiarly reversed from that of the company, although they were totally integrated within it.