Antonisen is a Danish surname meaning "son of Anton." It follows the common Scandinavian patronymic tradition, where the suffix -sen (derived from søn, "son") indicates lineage. This naming pattern was widespread in Denmark, Norway, and Sweden from the late Middle Ages into the 19th century, gradually shifting from a dynamic patronymic (where the suffix changed each generation) to a fixed family name. The root name Anton is itself a short form of the Roman family name Antonius, which is of Etruscan origin. The feminine form Antonia was also common in ancient Rome. Through Latin, the name spread across Europe, often associated with Saint Anthony the Great (c. 251–356), the Egyptian desert father considered a founder of Christian monasticism. Later, the 13th-century Saint Anthony of Padua, a Franciscan monk known for his powerful preaching, further popularized the name throughout Catholic Europe. In Russian culture, the diminutive Anton is well known through writers like Anton Chekhov, but the patronymic form Antonisen is distinctly Danish. Related surnames include Anthonsen and Antonsen, which are variant spellings reflecting the same etymological root. In other languages, similar names built on the same stem include Russian Antonov (and its feminine Antonova), Bulgarian Antov/Antova, and Macedonian Andonov/Andonova. These demonstrate how the Latin root evolved across Slavic and Scandinavian linguistic landscapes. The prevalence of such patronymics in Denmark today is moderate; the name remains relatively rare compared to its variant Antonsen.Meaning: Son of AntonOrigin: Latin (ultimately Etruscan)Type: Patronymic surnameUsage regions: Denmark