The name Agustin is derived from the Latin name Augustinus, which was originally a Roman family name. It is believed to have its roots in the Latin word "augustus," meaning "venerable" or "consecrated." The name gained widespread popularity due to its association with St. Augustine of Hippo, one of the most influential figures in the history of Christianity.

St. Augustine, born Aurelius Augustinus in 354 AD in the Roman province of Numidia (present-day Algeria), was a renowned philosopher, theologian, and bishop. His seminal work, "The Confessions," is considered one of the most influential autobiographical works in Western literature. St. Augustine's profound impact on Christian theology and philosophy played a significant role in the widespread adoption of the name Agustin throughout the Christian world.

The name Agustin first appeared in historical records during the Middle Ages, particularly in Spain and other parts of Europe influenced by the Roman Catholic Church. It was a popular name among the clergy and religious orders, as well as among the nobility who sought to honor St. Augustine's legacy.

One of the earliest recorded examples of the name Agustin can be found in the 12th century, when Agustin of Hippo, a Spanish monk and scholar, wrote a treatise on the Augustinian rule. Another notable figure was Agustin Antolinez, a 16th-century Spanish architect and sculptor who contributed to the construction of the El Escorial monastery in Madrid.

Throughout history, several notable individuals have borne the name Agustin. Among them are Agustin of Canterbury (died 604 AD), the first Archbishop of Canterbury and a founder of the English Church; Agustin of Dacia (c. 1285-1285), a Danish philosopher and theologian; Agustin Salucio (1523-1592), an Italian Dominican friar and theologian; Agustin Lara (1897-1970), a renowned Mexican composer and songwriter; and Agustin Barrios (1885-1944), a celebrated Paraguayan guitarist and composer.

The name Agustin has remained popular throughout the centuries, particularly in Spanish-speaking countries and regions with a strong Roman Catholic tradition. Its connection to St. Augustine and the rich cultural heritage associated with the name has ensured its enduring popularity and significance.