Which preposition to use with spartacists

in Occurrences 1%

The Spartacists in Germany, the Radical Socialists in Austria, and the Communists in Hungary were the best organized and most vigorous of the political groups in those countries and were conducting an active and seemingly successful propaganda among the starving and hopeless masses, while the Russian duumvirs, Lenine and Trotsky, were with funds and emissaries aiding these movements against established authority and social order.

Which preposition to use with  spartacists