* Dutch (his native language)
* French (the language of the court of the Habsburgs, the rulers of the Netherlands at the time)
* Spanish (also spoken by the Habsburgs)
* Italian (Rubens spent time in Italy and learned the language)
* Latin (the language of scholarship and diplomacy at the time)
Some sources suggest he may have also spoken German, but this is less certain.
It's important to note that while Rubens likely spoke these languages, his fluency in some may have been greater than others.