This was followed by the death of king Władysław IV on 20 May 1648, and Chancellor Jerzy Ossolinski called for a congress of notables in Warsaw on 9 June, at which Zaslawski, Ostroróg and Koniecpolski were designated provisional commanders, and Adam Kisiel was instructed to enter into negotiations with Bohdan Khmelnytsky.

[6]: 469 An advance regiment commanded by Koniecpolski and Ostroróg crossed the Ikopot River at Rosolivtsi on 6 September 1648, and encountered a Cossack garrison near Starokostiantyniv, who overnight abandoned the town to the Crown Army.

[6]: 475  "Everyone else began to flee, leaving behind wagons, cannon, and all kind of supplies, only the sick and maimed remained", not stopping at Starokostiantyniv, Koniecpolski went to Brody, Ostroróg to Olesko, Zaslawski to Vyshnivets.

[2] The Poles left behind an "immense, unheard-of booty", including a hundred thousand loaded wagons, and the "Cossacks then threw themselves, completely unarmed, into looting the camp", which "significantly weakened the victor's desire to launch a pursuit.

[6]: 477  A few days later, Bohdan Khmelnytsky seized Zbarazh, "the residence of the Cossack's greatest enemy, Jeremi Wiśniowiecki", continued on to siege Lviv from 28 September until 15 October 1648, leaving after that city paid 500,000 złoty worth of "money, metal, goods, and supplies" (330,000 went the Tatars).