Evidence of the oldest settlement in Dubnice comes from the Early Stone Age. At the end of the 5th and the beginning of the 6th century, the first Slavs came to us.
In the locality of Kvášovec, a settlement with a dwelling dated to ceramics was found in the younger Slavic, ie Greater-Moravian period; in the locality of Húštik (Veľký Kolačín), two settlements of Slavic ancestors were discovered (Great Moravian period).
The oldest written mention of Dubnica is in a document dating back to 1193, in which Dubnica is mentioned as a property hereditarily used by the brothers Vratislav and Piskin. Another report about Dubnica is from 1276, when Samsom and Jakub, the sons of Čepka (Vratslav's son), sold Dubnica to their sister Oltuman's husband. The document is significant in that it mentions the church dedicated to St. To the apostle James. There are relatively few municipalities that have such a specific document from the 13th century documented the existence of the church and its patronage - consecration.
We do not know when Dubnica was a peasant village belonging to Oltuman's descendants, perhaps at the beginning of the 15th century the family died out, because in 1439 Dubnica was already mentioned as the property of the Trenčín castle estate and remained so until the end of feudalism.
At the end of the 16th century, Count Štefan Illesházy took over the advance of the Trenčín estate (which also included Dubnica), for which he paid Rudolf II. 201,065 tolars.