Boris was now virtually the monarch of Russia, reigning, however, in the name of Feodor. We have before mentioned that Poland was an elective monarchy. Immediately upon the death of a sovereign, the nobles, with their bands of retainers, often eighty thousand in number, met upon a large plain, where they spent many days in intrigues and finally in the election of a new chieftain. Boris Gudenow now roused all his energies in the endeavor to unite Poland and Russia under one monarchy by the election of Feodor as sovereign of the latter kingdom. The Polish nobles, proud and self-confident, and apprised of the incapacity of Feodor, were many of them in favor of the plan, as Boris had adroitly intimated to them that they might regard the measure rather as the annexing Russia to Poland than Poland to Russia. All that Boris cared for was the fact accomplished. He was willing that the agents of his schemes should be influenced by any motives which might be most efficacious. The Polish diet met in a stormy session, and finally, a majority of its members, instead of voting for Feodor, elected Prince Sigismond, a son of John, King of Sweden. This election greatly alarmed Russia, as it allied Poland and Sweden by the most intimate ties, and might eventually place the crown of both of those powerful kingdoms upon the same brow. These apprehensions were increased by the fact that the Crimean Tartars soon again began to make hostile demonstrations, and it was feared that they were moving only in accordance with suggestions which had been sent to them from Poland and Sweden, and that thus a triple alliance was about to desolate the empire. The Tartars commenced their march. But Boris met them with such energy that they were driven back in utter discomfiture. The northern portion of Asia consisted of a vast, desolate, thinly-peopled country called Siberia. It was bounded by the Caucasian and Altai mountains on the south, the Ural mountains on the west, the Pacific Ocean on the east, and the Frozen Ocean on the north. Most of the region was within the limits of the frozen zone, and the most southern sections were cold and inhospitable, enjoying but a gleam of summer sunshine. This country, embracing over four millions of square miles, being thus larger than the whole of Europe, contained but about two millions of inhabitants. It was watered by some of the most majestic rivers on the globe, the Oby, Enisei and the Lena. The population consisted mostly of wandering Mohammedan Tartars, in a very low state of civilization. At that time there were but two important towns in this region, Tura and Tobolsk. Some of the barbarians of this region descended to the shores of the Volga, in a desolating, predatory excursion. A Russian army drove them back, pursued them to their homes, took both of these towns, erected fortresses, and gradually brought the whole of Siberia under Russian sway. This great conquest was achieved almost without bloodshed.