A journey of political importance had taken the Grand Duke to these distant provinces of Central Asia. After passing through the principal Siberian cities, the Grand Duke, who traveled en militaire rather than en prince, without any parade, accompanied by his officers, and escorted by a regiment of Cossacks, arrived in the Trans-Baikalcine provinces. Nikolaevsk, the last Russian town situated on the shore of the Sea of Okhotsk, had been honored by a visit from him. Arrived on the confines of the immense Muscovite Empire, the Grand Duke was returning towards Irkutsk, from which place he intended to retake the road to Moscow, when, sudden as a thunder clap, came the news of the invasion.

He hastened to the capital, but only reached it just before communication with Russia had been interrupted. There was time to receive only a few telegrams from St. Petersburg and Moscow, and with difficulty to answer them before the wire was cut. Irkutsk was isolated from the rest of the world.

The Grand Duke had now only to prepare for resistance, and this he did with that determination and coolness of which, under other circumstances, he had given incontestable proofs. The news of the taking of Ichim, Omsk, and Tomsk, successively reached Irkutsk. It was necessary at any price to save the capital of Siberia. Reinforcements could not be expected for some time. The few troops scattered about in the provinces of Siberia could not arrive in sufficiently large numbers to arrest the progress of the Tartar columns. Since therefore it was impossible for Irkutsk to escape attack, the most important thing to be done was to put the town in a state to sustain a siege of some duration.