When and how did the invasion of the German crusaders into the Novgorod borders begin?

It was a crusade. We can say that during the Mongol rule, Russia was greatly weakened. This became the reason that the Catholic Church and the knightly states wanted to annex part of the lands of Russia, as well as spread the Catholic faith in that region. So in 1242 there was a campaign against Novgorod. But the German knights in that campaign were defeated, in connection with which, all plans for the Russian lands of the enemy were failed.