Sakhalin is known as the "Far East Kuwait", and its interior is rich in oil and gas. According to later generations, Sakhalin Island has oil reserves of up to 7 billion tons, in addition to rich coal resources, the island is also very rich in water resources, more than 6,000 rivers, so the corresponding forestry resources are also quite rich, the forest coverage rate is 84%.

The Far East is China's far northern frontier, the control is quite weak, continue to the north and west more sparsely populated, in history this land called the Siberian Plain by later generations few countries set foot in, this land lives a large number of indigenous tribes, most of them are uncivilized people, and the Jurchen people in the early period, fishing and hunting for a living.

However, from the fifties of the sixteenth century, in distant Europe, driven by fur interests, Tsarist Russia began to expand into Siberia.

After nearly a hundred years of expansion, Tsarist Russia established several Cossack cavalry units to invade Siberia by pardoning criminals and armed prisoners of war.

In 1595, the Russians established Narem in the middle and upper reaches of the Ob River, not far from the mouth of the northern tributary Paidugina River; In 1604, Tomsk was founded on the banks of the Tom River, a tributary of the middle and upper reaches of the Ob River, sixty-five kilometers from the mouth of the river;

By 1618, the city of Kuznetsk was established at the mouth of the Kondoma River, an upper tributary of the Tom River, marking the completion of the Russians' discovery and annexation of Western Siberia.

In 1618, the Russians built the Yeniseisk fortress at the confluence of the middle and upper reaches of the Yenisei River with a small tributary on the left bank.

In 1626, the Russians established the Yakutsk fortress on the west bank of the bow-shaped bend in the middle reaches of the Lena River, at the easternmost point of the Lena River (130° east longitude), which became a new forward base for the Russian expedition.

In 1638, the Russians reached the Sea of Okhotsk and established the fortress of Okhotsk at the mouth of the Ohota River in the middle of the coast, and since then the Russians have reached the eastern shore of the Pacific Ocean.

While the Russians were expanding into the Pacific Ocean from the base of the Yakutsk fortress, the Russians also set their sights on the Heilongjiang and Ussuri river basins in the south.

In May 1640, during the first battle of Gaizhou between the Manchu Qing and the Tiance Army, the Cossack expeditionary force led by Vasily Boyakov, the secretary of the Yakutsk fortress, attacked a number of Daur and Oroqen tribes in the Heilongjiang River valley, and brutally killed more than 400 ethnic minorities in the region.

After that, Poyakov sent a letter to the tsar and threatened that as long as he sent 500 troops and built three fortresses, he could conquer Heilongjiang.

In his letter to the Tsar, Poyakov provided detailed information on the Heilongjiang River valley and stressed the need to conquer it. In 1647, Tsarist Russia sent Khabarov, the governor of Yakutsk, to lead an army of more than 400 troops to continue to invade the Heilongjiang River valley and forcibly occupy the city of Yaxa.

What was the size of the Cossack expeditionary force led by Poyakov? There were one hundred and fifty-eight men in all, but they were very well armed, all cavalry, armed with arquebuses and sabers, compared to the harpoons and bone arrows of Siberia.

The powerful Cossacks relied on the armed forces of dozens and hundreds of men to constantly invade and infiltrate Siberia, and finally took this vast territory.

Poyakov was accustomed to fighting in the land of Siberia, for he had never met regular armed forces.

On August 9, on the north bank of the mouth of the Emur River, the former Daur Ola tribe had been exterminated by the Cossack expeditionary force, and Boyakov was leading his troops to count the spoils of victory, and the booty of the Cossacks included women in addition to furs.

"Major Poyakov, we found a dozen fine sable skins, as well as a large number of fox and roe deer skins." A Cossack captain excitedly said to Boyakov.

Boyakov laughed and said, "I didn't expect that the results in such a small tribe would be so rich, and the women would be so white and tender. What a rich land, where Russia should build a city, Yakutsk is so far away. ”

"Yes, Major, this season is the right time for hunting." The captain also smiled: "Heilongjiang is not far from here, so do we still want to continue south?" ”

"Why not? It would be better for us to return to Yakutsk before the arrival of winter, because our soldiers need more women. Boyakov smiled greedily.

The two were talking and laughing, and there was a sound of horses' hooves coming from far and near, and after a moment a Cossack cavalryman rolled his saddle and fell off his horse, and shouted to Poyakov: "Mr. Major, we may be in trouble, an army has been found in the southeast. ”

Poyakov's face turned cold instantly, and he asked sharply: "Tonisky, you bastard, you mean that you discovered the army?" Are there any other armies in this land besides our Cossacks, and how many of them there are? How many cavalry? Is it a Ming or a Qing person?

Toniski said: "Mr. Major, judging from the uniform clothing, it is indeed an army, but I can't tell which country's army, but they have no cavalry, about a hundred or more people, and a large number of vehicles. ”

"Major Boyakov, it's very likely that the Qing people who can get here are Qing people." The Cossack captain next to him said: "Those Tatars are pigs with braids, and they are not worthy of being our Cossacks' opponents at all." ”

The information of this time and space is blocked, and Russia knows very little about the situation in Liaodong and Daming in the south.

"Oh well, let's gather the guys and greet our guests." Poyakov did not take this army to heart.

It is true that formed armies are more difficult to deal with than indigenous tribes, but Boyakov thinks that this is all there is to it. So far, the Russian Empire and the Qing Empire have not had more substantive contact, but the Russians know more about the South than the Qing Empire, because that is where their interests lie.

The Heilongjiang River basin was the farthest sphere of influence reached by the Manchu Qing Dynasty at present. In the second year of Chongde of the Qing Dynasty (1637), the castles of Yaxa, Duochen, Wukul, Assazin, and Duojin in the Heilongjiang River basin elected Bomu Bogol, the leader of various ethnic groups in the region, as the general leader, and refused to pay tribute to the Manchu Dynasty, which led to a rebellion, and Huang Taiji began to use troops in this place.

In the fourth year of Chongde in the Qing Dynasty (1639), Bomu Bogol was defeated and died, and the Qing army captured more than 4,900 strong men, more than 5,000 women and children, all of whom were sent to Shengjing and incorporated into the Eight Banners. The Manchu Qing Dynasty demolished and relocated most of the border people, and then set up Ningguta Zhangjing to manage the affairs of the Heilongjiang and Ussuri River basins, and Ningguta became the political center of the region.