Biggar was born at Gateshead and received his medical training at St Bartholomew's Hospital; while there he won the junior and senior Platt Scholarships; the Matthew Duncan Prize; the Herbert Prize; the Parkes Memorial Prize; and a silver medal at the first Montefiore Prize. He held a number of resident posts at Bart's, and then decided to make the Army his career, and won the Ronald Martin gold medal at the Royal Army Medical College, London, in 1933. During 1937-39 he served in India, and in 1939 was appointed professor of military surgery and consultant surgeon to the Army. He attained the rank of Lieutenant-Colonel, and was appointed an honorary surgeon to the King. Biggar finally retired from the Army in December 1940, and died in 1966 some 25 years after he left the army.