In 1637 the Cossacks reached and established themselves in Yakutsk. In 1639 by the far northern route they pierced to the Sea of Okhotsk. In 1644 a party reached the delta of the Kalyma, and curiously speculated upon the mammoth tusks which they found. In 1648, on the Cellinga River beyond Lake Baikal they built Fort Verhneudinsk. Had their tide of conquest now rolled southward, up the Cellinga Valley, the Russian Eagles might to-day be flying over Peking. Only the Kentai Mountains were between them and prostrate Mongolia, enfeebled by the internecine warfare of her rival khans. From Mongolia, the road, worn by so many conquerors of old, leads fair and clear to the Chi-li Province and the heart of China. But they passed this gateway by, those old Cossack heroes, as the railway builders have passed it by, to press with Poyarkov to the Pacific; to conquer, with Khabarov, the Amur; to meet in desperate conflict the whale-skin cuirassed Koriats of the coast; to battle with the Manchu in conflicts where “by the Grace of God and the Imperial good fortune, and our efforts, many of those dogs were slain”; to fight until but an unvanquished sixty-eight were left of the garrison of eight hundred in beleaguered Albazin. The current of conquest passed by this door to China, but the swelling stream of commerce searched it out. In 1638, the Boyar Pochabov, crossing Baikal on the ice, broke the first way to Urga, the capital of the Mongolian Great Khan, and gained the friendship of the monarch. In the interests of trade, the deputies of the Czar Alexei Michailovitch followed up the opening with an embassy in 1654 to the Chinese Emperor himself. Over steppe and mountain and desert the mission wound its weary way to Kalgan, the outpost city beside the Chinese Wall, and then on to Peking, bearing to the Bogdo Khan, the Yellow Czar, the presents of Chagan Khan, the White Czar. From the Forbidden Palace at Peking were started back, four years later, return presents, including ten _puds_ of the first tea that reached Russia. With the presents came a message that drove flame into the bearded cheeks of the Czar and set his Muscovite boyars to grasping their sword-hilts. “In token of our especial good-will we send gifts in return for your tribute.” Thus, the Chinese Emperor. The answer of the Czar started another legation plodding across a continent, and the retort was thrown at the feet of his Yellow Majesty. It was a summons forthwith to tender his vassalage to Russia. The Czar’s gauntlet had been hurled across Asia. But all it brought was beggary to the traders who had begun to press along the newly-opened route to a commercial conquest of the East.