The German princes who oppose Henry IV…

The German princes who oppose Henry IV had held a conference in Speyer in August 1087.

Ladislaus had sent envoys to their meeting and "promised that he would assist" them "with twenty thousand knights, if it became necessary", according to Bernold of St. Blasien.

This report also proves that Ladislaus recognized Victor III as legitimate pope against Clement III, who had been elected pope on Henry IV's initiative.

However, Ladislaus provided no support to the German anti-king Hermann of Salm after he was informed that Solomon had died in Bulgaria during a military action against Constantinople in 1087.

Even so, in 1090 Bishop Jaromír of Prague visit Ladislaus—who was "his old friend", according to Cosmas of Prague—after he had decided to submit a complaint at the Holy See against King Vratislaus II of Bohemia's decision of the division of his diocese.