A chapel dedicated to St John the Baptist is recorded here by the 1290s, and the village is simply named after it — Ján is John. The early Gothic church of the late thirteenth century still stands; it was widened to the south in the fourteenth century and given ribbed vaulting. Between 1352 and 1360 Bohumír's descendants established their seats in the village, and the family took the village's name in turn, as the Szentiványi — the Svätojánsky, the "of St John" family. At their height they controlled roughly a third of Liptov and worked silver and gold in the Boca valley to the south, which is why one of the mining villages up there is still called Svätojánska Boca.Kaplnka zasvätená Jánovi Krstiteľovi je tu doložená v deväťdesiatych rokoch 13. storočia a obec je jednoducho pomenovaná po nej. Ranogotický kostol z konca 13. storočia stojí dodnes; v 14. storočí ho rozšírili na južnú stranu a zaklenuli rebrovou klenbou. V rokoch 1352 – 1360 si Bohumírovi potomkovia zriadili v obci svoje sídla a rod si vzal meno dediny — Szentiványiovci, po slovensky Svätojánski. V čase najväčšej moci ovládali zhruba tretinu Liptova a v Bocianskej doline na juhu ťažili striebro a zlato; práve preto sa jedna z tamojších baníckych dedín dodnes volá Svätojánska Boca.
