The name Reginald is of Germanic origin, derived from the elements "regin" meaning "counsel" or "advice" and "wald" meaning "rule" or "power". It first appeared in the 8th century as a compound of the Old German words "ragin" and "waldan", and was initially a title or descriptive name rather than a proper given name.

The earliest recorded use of Reginald as a personal name dates back to the 9th century, when it was borne by a Frankish nobleman named Reginald of Herbauges. In the 11th century, it gained popularity among the Norman nobility and was brought to England after the Norman Conquest of 1066.

One of the most notable historical figures named Reginald was Reginald of Durham, an English monk and chronicler who lived from around 1070 to 1120. His work, the "Libellus de Admirandis Beati Cuthberti Virtutibus" (The Little Book of the Wonderful Virtues of St. Cuthbert), is an important source of information about the Anglo-Saxon period in Northumbria.

Another significant bearer of the name was Reginald Fitzurse, one of the four knights who assassinated Thomas Becket, the Archbishop of Canterbury, in 1170. This event was a pivotal moment in the conflict between King Henry II and the Church.

In the 13th century, Reginald of Piperno, an Italian Dominican friar, wrote the influential theological work "Summa de Poenitentia et Matrimonio" (Summa on Penance and Matrimony). He lived from around 1230 to 1290.

During the Renaissance, Reginald Pole (1500-1558) was an influential figure in the English Reformation. He was a Catholic cardinal and the last Catholic Archbishop of Canterbury before the Church of England's break with Rome.

In the 17th century, Reginald Scot (1538-1599) was an English writer and country squire who authored the influential work "The Discoverie of Witchcraft", a skeptical and critical examination of the contemporary belief in witchcraft.

While the name fell out of fashion in some parts of Europe, it remained popular in England and Ireland throughout the Middle Ages and into modern times. It has been borne by many notable individuals, including writers, politicians, and clergy.