The name Allen is derived from the medieval English surname of Anglo-Saxon origin. It is believed to have originated from the Old English pre-7th century word "alor" or "alor-ac", meaning "valley" or "meadow of alders". This suggests that the name may have been used to identify people who lived in or near an alder grove or valley.

The name Allen has been in use since the Middle Ages, and it can be found in various historical records and documents from that time period. One of the earliest recorded instances of the name dates back to the Domesday Book of 1086, where it was spelled as "Alanus".

In the 12th century, the name Allen appeared in the form of "Alain" in the famous medieval French epic poem, "The Song of Roland". This suggests that the name may have had some popularity in France during that time.

Throughout history, there have been several notable figures who bore the name Allen. One of the most famous was Allen of Brittany (1084-1119), a Breton knight who fought alongside William the Conqueror during the Norman Conquest of England in 1066.

Another well-known Allen was Allen of Ghent (c. 1420-1475), a Flemish Renaissance painter and manuscript illuminator who worked for the Dukes of Burgundy in the 15th century.

In the field of literature, Allen Tate (1899-1979) was an American poet, essayist, and literary critic who was a leading figure in the Southern Agrarian movement and the New Criticism school of literary theory.

In the realm of science, Allen B. DuMont (1901-1965) was an American engineer and inventor who played a significant role in the development of early television technology. He founded the DuMont Television Network, one of the world's first commercial television networks.

Lastly, Allen Ginsberg (1926-1997) was an American poet and a leading figure of the Beat Generation. His influential works, such as "Howl" and "Kaddish", explored themes of counterculture, drugs, and sexuality, and helped to shape the American literary landscape of the 20th century.