No, I failed it - when Radziwill gave order to conquer a fortress, i captured Krakow for him, he stay there and gave next order, capture Kyiv. Me with lords went there, and when we besieged city, Swedish or Polish army came and besieged Krakow with Radziwill inside, I tryed come back to help him, but was to late - enemy capture city and with this storyline quest fails