Pre-talmudic Judaism converted non-Jews, sometimes by force and sometimes by persuasion.

See Josephus, Antiquities_of_the_Jews, regarding a conquest in 125 BCE:

Hyrcanus … subdued all the Idumeans; and permitted them to stay in that country, if they would circumcise their genitals. … they were hereafter no other than Jews.

Some scholars regard Josephus' writings, such as Against_Apion, as being explicitly missionizing.

Non-Jewish writers note Jewish conversions, e.g. Valerius Maximus wrote that circa 139 BCE, some Jews were deported from Rome because the Jews had attempted "to infect the Roman customs with the cult of Jupiter Sabazius." A Roman named Hispalus expelled Jews from Rome for excessive missionary work.