Many Polish nobles and soldiers are fighting for the second False Dmitry at this time, but Sigismund and the troops under his command do not act in support of Dimity’s claim to the throne—Sigismund wants Russia himself.

The entry of the King of Poland-Lithuania into Russia causes the majority of False Dmitriy II's Polish supporters to desert him and contributes to his eventual defeat.

A Commonwealth army under the command of Hetman Stanisław Żółkiewski, who is generally opposed to this conflict, but cannot disobey a king's orders, crosses the border, and on September 29, 1609 lay siege to Smolensk, an important city that Russia had captured from Lithuania in 1514.

Smolensk is manned by fewer than a thousand Russian men commanded by the voivod Mikhail Shein, while Żółkiewski commands twelve thousand troops.

However, Smolensk has one major advantage: the previous Tsar, Boris Godunov, had sponsored the fortification of the city with a massive fortress completed in 1602.

The Poles find it impenetrable; they settle into a long siege, firing artillery into the city, attempting to tunnel under the moat, and building earthen ramparts, remnants of which can still be seen today.

At the same time, ...