Complex sentence: Andrew's envoys and Leopold VI of Austria signed a treaty on 6 June, which put an end to the armed conflicts along the Hungarian-Austrian border and compelled Leopold VI to pay an indemnification for the damages that his troops had caused in Hungary.
Split into simpler sentences: Andrew's envoys and Leopold VI of Austria signed a treaty on 6 June, which ended the armed conflicts along the Hungarian-Austrian border. As part of the treaty, Leopold VI paid an indemnification for the damages that his troops had caused in Hungary.