Slavic language belongs to a family of IE languages found in Europe. The origins of Slavic speakers should be among ancient Europeans.

Slavs were settled people, whereas Sarmatians were nomads living in the steppes. The two groups of people belonged to different cultures. Sarmatians and Slavs met in a place settled by Slavs into which Iranic speaking peoples (possibly Sarmatians) moved or pushed by their enemies. One such group of pople consisted of Slavs and Iranic speaking peoples were the Antes people accounted in historical chronicles by Procopius and Jordanes. The Antes lived between Dnieper and Dniester Rivers in 6-7th century: http://en.wikipedia.org/wiki/Antes_people

well, i actually meant some possible more recent common roots between them, the way there were more recent common roots with Balts.