According to the treaty of February 4, 1610, signed near Smolensk by King Sigismund III and the Muscovite embassy, prince Władysław IV, after accepting Orthodoxy, was to take the throne of Russia.

On April 6, 1617, prince Władysław set out from Warsaw on a march to Moscow in order to obtain the crown of the Tsar of Russia.

The Cossacks cunningly lured Muscovite regiments out of the city, and stormed the fortress with the remnants of the Moscow army on the next night.

[3] In late July and early August, Sahaidachny sent colonel Mykhailo Doroshenko, leading a 10,000-strong detachment, to raid the Ryazan region.

[4] Having joined forces and determined through the envoys the meeting place of the Polish and Cossacks troops in Tushino, Sahaidachny continued his campaign.

After two attempts to storm the city on September 7, Sahaidachny was forced to abandon the siege in order to catch up with King Władysław near Moscow.

[5] After the unsuccessful siege of Mikhailov, Petro Sahaidachny sent about 2,000 Cossacks under the leadership of Fedir Boryspilets to the nearby approaches of Moscow from the south – to Meshchera Lowlands.

One of the tasks of this maneuver was to divert the enemy's attention from the planned forcing of Oka north of Mikhailov by the main Cossack army.

[6] To confront the Cossacks, tsar Mikhail Romanov sent an army of 7,000 under the leadership of Dmitry Pozharsky and prince Grigoriy Volkonskiy.

On September 12, Petro Sahaidachny received a letter from prince Władysław notifying that he was leaving Mozhaisk for Moscow, and ordered the hetman to immediately head for the Simon's Monastery.

[7] The next day, a Cossack council was gathered, where it was decided to begin a raid on Moscow on September 14, without waiting for Fedir Boryspolets' return.

On September 15–16, the Cossacks laid siege to Zaraysk, while concentrating the troops near the confluence of Osyotr and Oka rivers and preparing for the crossing.

Shortly afterwards, Cossack troops encamped near Cherkizov, from where on September 24 the envoys, Colonels Mykhailo Doroshenko and Bohdan Konsha, were sent by Sahaidachny to determine the exact time and place of his arrival near Moscow.

On September 28, the ambassadors arrived in Zvenigorod and it was agreed with the Polish-Lithuanian command that a reunion of troops would take place on October 3 in the village of Tushino.

In the letter, the hetman wrote: "May the Lord God Almighty be bringer of good fortune and blessing in achieving this plan to appoint the honor of the kingdom to your royal mercy, and that the people stubborn at the feet of his majesty were subdued.".

On the eve of Sahaidachny's arrival, Lithuanian hetman Jan Karol Chodkiewicz devised a plan to capture Moscow.

The Cossack army was divided into several parts, some of them went to storm the fort from the Moskva river, the rest had to act as a reserve and distract the tsarist troops from the main directions.

Meanwhile, some Cossack detachments continued to attack the cities north and northwest of Moscow, ravaging Yaroslavl and Vologda counties, thereby undermining the economic resources of Muscovites.

At the end of October, P. Sahaidachny sent an 8,000-strong army south of Moscow to the lands adjacent to the left bank of the Oka river.

Assessing these events, Jan III Sobieski pointed out that it was because of this raid that the Muscovites were horrified and the Cossacks "persuaded their commissars to negotiate as soon as possible."

Poland gained control over Belarusian and Ukrainian lands, which were previously under the rule of Moscow: Smolensk, Chernihiv and Novgorod-Siversk – 29 cities overall.

Most of them, under the leadership of Sahaidachny, moved along the left bank of the Oka river in the direction of Przemyśl, Belyov, Bolkhov, and then to Kyiv.

According to D. Yavornytsky, upon his arrival in Kyiv, Petro Sahaidachny accepted the title of "Hetman of Ukraine" and started to rule that part of it that recognized itself as Cossack.