Agner Erlang was born on January 1, 1878 in Lonborg, Denmark, the son of a school teacher. Erlang studied mathematics at the University of Copenhagen, graduating with a master's degree in 1901. He taught for several years before joining the Copenhagen Telephone Company in 1908, the same company that employed the engineer and mathematician Johan Jensen. Erlang remained at the telephone company for the next 20 years. He died on February 3, 1929 in Copenhagen.
Motivated by applied problems at the telphone compnay, Erlang made important contributions in queuing theory and the Poisson process. The distribution that governs the arrival times in the Poisson process (a special case of the gamma distribution) is called the Erlang distribution in his honor.