Complex sentence: A few months later, however, Ivaylo managed to break through the Mongols and his army appeared in the outskirts of Tarnovo and Ivan Asen III was blocked in the capital.
Split into simpler sentences: A few months later however, Ivaylo managed to break through the Mongol blockade. His army appeared in the outskirts of Tarnovo and Ivan Asen III was blockaded in the capital.