The first half of the 20th century was perhaps the most turbulent in history. Two world wars and numerous smaller conflicts resulted in an unprecedented number of changes. Some of the leaders made an indelible mark on their nation and the world; others are scarcely remembered.

Nearly 1,200 emperors, kings, queens, presidents, prime ministers, premiers, emirs, and other heads of state or government served from 1900 through 1945, and all are included in this comprehensive reference work. Each biographical profile is packed with data.