 Complete the following phrase:  The attack on Europe was planned and executed by Subutai, who achieved perhaps his most lasting fame with his victories there. Having devastated the various Rus principalities, he sent spies into Poland and Hungary, and as far as eastern Austria, in preparation for an attack into the heartland of Europe. Having a clear picture of the European kingdoms, he prepared an attack nominally commanded by Batu Khan and two other familial-related princes. Batu Khan, son of Jochi, was the overall leader, but Subutai was the strategist and commander in the field, and as such, was present in both the northern and southern campaigns against Rus principalities. He also commanded the central column that moved against Hungary. While Kadans northern force won the 