The name Trevor is of Welsh origin, deriving from the word "tref" meaning "town" or "settlement." It is believed to have emerged during the Middle Ages, around the 12th or 13th century, when Welsh names were becoming more prevalent.

One of the earliest recorded instances of the name Trevor can be found in the Domesday Book, a comprehensive survey of England and Wales commissioned by William the Conqueror in 1086. Here, the name appears as a place name, suggesting it may have initially been used as a surname before transitioning into a given name.

The first known historical figure to bear the name Trevor was Trevor the Monk, a Welsh clergyman and historian who lived in the late 12th century. He is best known for his work "Brut y Tywysogion" (Chronicle of the Princes), a valuable record of Welsh history and events from 682 to 1196.

In the 14th century, Sir Trevor de Blaney, a prominent Welsh landowner and military commander, played a significant role in the Wars of Scottish Independence, fighting alongside Edward I against the Scots.

During the English Renaissance period, Trevor Vaughan (1544-1604) was a renowned Welsh poet and scholar, known for his poetic works in both Welsh and English.

In the 17th century, Trevor Hill (1616-1653) was an English Puritan minister and author who played a prominent role in the English Civil War, supporting the Parliamentarian cause.

Another notable figure was Trevor Barlow (1676-1737), an English clergyman and author who served as the Bishop of Lincoln from 1723 until his death.

Throughout history, the name Trevor has been borne by various individuals from different walks of life, including writers, artists, politicians, and military leaders. Its rich Welsh heritage and historical significance have contributed to its enduring popularity over the centuries.