He attended the Panslavist congress at Moscow in 1867.
This new departure was considered by the Russians - especially by those of the Panslavist party - almost as an apostasy, and it was decided to oppose Prince Milan and his supporters, the Servian Progressives.
The policy of the nationalists, who now aimed at the political union, under the king-emperor, of all Serbo-Croats in Austria-Hungary - upwards of 4,50o,000 - was less visionary than the older Illyrism, and less aggressively Panslavist.
In 1888 the moderate Opposition also lost its leader, Bishop Strossmayer, who was censured by the king on account of his famous Panslavist telegram to the Russian Church (see Strossmayer).