The orthodox would argue that it was catholicism that was created by the great schism. But for both sides the actual date of the schism matters little, the divide between east and west was already forming long before then. Tsar Boris the 1st actually sent letters to the pope in Rome and the patriarch in Constantinople asking both of them for Christian teaching, it's debated wether he did this cynically or innocently, but either way he was "playing both sides" even before the schism, if anything he accelerated it somewhat.
