The name Justyn is a variant of the Latin name Justinus, which derives from the word "justus" meaning "just" or "upright." The name has its roots in ancient Rome, where it was used as a personal name during the Roman Empire.

In the early Christian era, the name Justinus gained popularity as it was borne by several early Christian saints and martyrs. One of the most notable was Saint Justin Martyr, a philosopher and Christian apologist who lived in the 2nd century AD and is venerated as a saint in the Catholic, Anglican, and Orthodox churches.

The name Justyn emerged as a spelling variation in the medieval period, particularly in English-speaking regions. It was likely influenced by the Old French spelling "Justyn" or the Norman French "Justyn."

One of the earliest recorded instances of the name Justyn can be found in the Domesday Book of 1086, which was a survey of landowners in England commissioned by William the Conqueror. The name appeared as "Justyn" in this historical record.

Throughout history, several notable individuals have borne the name Justyn, including:

1. Justyn Martyr (c. 100-165 AD), a Christian philosopher and apologist who is considered a saint in various Christian traditions.
2. Justyn of Galen (fl. 4th century AD), a Roman historian and author of a world history known as the "Epitome of the Philippic History of Pompeius Trogus."
3. Justyn I (c. 450-527 AD), a Byzantine emperor who reigned from 518 to 527 AD.
4. Justyn II (c. 520-578 AD), a Byzantine emperor who ruled from 565 to 578 AD.
5. Justyn the Martyr (c. 1100-1179), an English Christian saint and martyr who was executed for his faith during the reign of Henry II.

The name Justyn has maintained a presence throughout history, particularly in Western cultures influenced by Latin and Christian traditions. Its association with the concept of justice and righteousness has likely contributed to its enduring appeal as a personal name.