Qi Jiguang used the Qi Family Army as a model and worked hard to train the troops for three years, which basically solved the chronic problem of the arrogance and laziness of the more than 100,000 Northern Army soldiers in Jizhen. In particular, the 30,000 newly recruited soldiers had been tempered and were elite.

The third thing he did was to explore a new set of tactics. Qi Jiguang knew that fighting the Tartars in the north and fighting the Japanese pirates in the south were two completely different things.

The south is a swampy area with dense rivers and lakes, which is not conducive to large-scale military operations or cavalry operations. Therefore, Qi Jiguang fought against the Japanese pirates with thousands of elite infantry, and he was able to be invincible relying on the Mandarin Duck Formation.

But the north is mostly open land, which is conducive to cavalry combat. The powerful Mongolian cavalry is good at riding and shooting, with super mobility, coming and going like the wind and clouds, erratic. And every time they go out in full force, there are tens of thousands of cavalry.

At this time, relying on infantry to use the Mandarin Duck Formation to fight back would be like hitting a rock with an egg.

Different battlefield environments require new strategies and tactics. Qi Jiguang did not dwell on his past glory and immediately began to study new tactics.

He knew very well that the advantage of cavalry lay in its speed. To defeat a powerful and lightning-fast enemy, he either had to have a faster and more powerful cavalry unit of his own, like Guanjun Hou did.

Or you have to try to slow down the enemy's speed and fight them with chariots like Wei Qing did.

The Ming Dynasty was seriously lacking in cavalry, and it took too long to train elite cavalry. Although it was a long-term plan, it could only be done gradually. Before that, the latter was obviously more realistic.

Of course, it was not a pure chariot formation... that would be too passive. He put in a lot of effort, tightened his belt, and formed a powerful army that combined chariots, cavalry, and infantry.

At the same time, Qi Jiguang also focused on tactical training based on actual conditions. He believed that when deploying troops, different strategies and tactics must be adopted according to different terrains, and one must not stick to the old ways and not know how to change.

He divided the terrain of Jizhen into three types. The first is the plain, the land within a hundred miles south of the pass; the second is the half-dangerous and half-easy land, near the border; the third is the narrow valley, outside the border. The wide plain is good for chariot battles, the half-dangerous and half-easy land is good for horse battles, and the valley is good for infantry battles. Based on this, he carried out mixed training of chariots, horses, and infantry, and let different arms play the leading role according to local conditions to maximize their advantages.

But the quality of the army can only be tested on the battlefield. After three years of careful preparation, the moment of the big test has finally arrived...

~~

The sound of hurried footsteps brought Qi Jiguang back to his senses.

He looked up and saw it was his general Feng Ziming.

"General." Feng Ziming clasped his fists and reported in a deep voice: "Scouts ahead reported that Brother Dong Huli led 50,000 Tartar cavalrymen and has left Daning and is heading south!"

Daning is Daningwei, called Bagou in Mongolian. It is known as the "thoroughfare between Liao and Mongolia and the gate of Yan and Zhao". Allusions such as "old horses know the way" and "looking at plums to quench thirst" all come from here. Since ancient times, it has been the only way for nomadic and farming peoples to conquer each other. After the Guochao recaptured Youyan, this place was also the station of the Beijing Xingdu Commandery.

But since the Battle of Tumu, the Ming Dynasty lost its glory and its national strength declined. Under the repeated attacks of various Mongolian tribes, its defense line continued to shrink.

Today, Daningwei has long been in name only and has become a pasture for the Wuliangha tribe. The Xifengkou Great Wall is the front line of the Ming army to resist their invasion.

There are mountains to the south of Daning. The Uriankhai came out in full force, obviously with only one purpose, which was to launch their annual looting during the autumn harvest in the Ming Dynasty.

Half a month ago, Qi Jiguang learned from merchants outside the Great Wall that the Wuliangha tribes were gathering. When he calculated that the time was almost up, he personally led his elite troops to the Xifengkou area where they were most likely to encounter the enemy, waiting for the Tartars to come.

"Haha, they are here!" As Marshal Qi's right-hand man, Hu Shouren also showed up. He stroked his beard excitedly and said, "I can finally have fun this time. Damn it, I haven't had a chance to fight in a few years!"

"Of course they will come." Qi Jiguang's brother Qi Jimei laughed out loud, "We didn't get any benefit from the repair of the border wall last year. If they don't plunder again this year, the Dong foxes won't be able to survive this winter."

The Mongolian tribes did not farm and had almost no handicraft industry. They could not even produce iron pots for boiling water and cooking. The Ming Dynasty also imposed a material embargo on them... Although Lao Xier helped with smuggling, it was far from meeting their needs.

In addition, due to the influence of the Little Ice Age, winters outside the Great Wall were extremely cold, and a large number of livestock froze to death every year. The tribes could only barely survive by plundering the interior every autumn.

Last year, Qi Jiguang repaired the border wall, but Dong Huli suffered a bloody defeat and returned empty-handed. Fortunately, he had saved some money before and bought food from Ming merchants in Shanxi and Liaodong, so he survived the long winter. But this spring, famine still occurred and many people starved to death.

So they will definitely come again this year, and will be even more ferocious and will not give up until they achieve their goal!

Seeing his generals rubbing their hands and eager to try, Qi Jiguang frowned slightly. In fact, according to his plan, this year should focus on defense. As long as Wuliangha returns empty-handed again, it will be exhausted by next year and will definitely be seriously damaged, or even collapsed.

But now the person in charge of the court is Gao Ge Lao, although Zhang Xianggong is still in charge of military affairs, everything must be done by Gao Xinzheng. This time Gao Xianggong issued a death order, Jizhen spent a million taels of silver from the court, this time they must win a big victory, otherwise they will be punished for missing the opportunity to fight.

Zhang Xianggong also wrote a letter to explain to Qi Jiguang that he and Gao Ge Lao were going to implement a plan to solve the northern border problem. The responsibility of firing the first shot fell on his shoulders. This battle must not only be won, but also won beautifully. Otherwise, it would affect the implementation of the entire plan.

Prime Minister Gao and his benefactor had already said so much, Qi Jiguang knew that it was useless to think too much, and the only thing he could do was to focus on winning this battle.

Shaking his head slightly, shaking off those inappropriate emotions, Qi Jiguang ordered in a deep voice: "Prepare the Flying Magic Lamp."

"Yes!" Qi Jimei responded and hurried down to the tower. Half an hour later, a large bonfire was lit in the city, and a large white balloon was slowly inflating under the action of the heat. The balloon was tied by four strong cables to prevent it from flying into the air.

This was exactly the hot air balloon that Zhao Hao had released in Yuyuantan. Qi Jiguang saw it flying over the Shenjiying Camp and realized that it would be very useful in the military. He asked Zhao Hao for it and copied it. He also gave it a domineering name, the Flying God Lamp.

Although after research, it was found that this thing could not fly autonomously and it depended on the wind to fly to where it went, which made Qi Jiguang's idea of ​​forming a formation and high-altitude bombing come to nothing. But it could conduct reconnaissance from a high altitude, and with the telescope invented by Zhao Hao, it could even see what was happening a hundred miles away. What else did it need a bicycle for?

Moreover, Qi Jiguang discovered that if a rope was tied and the Flying Magic Lantern was launched into the air on the spot, as long as the fire below was not kept burning, the Flying Magic Lantern could remain suspended in the air. In this way, when the two armies were facing each other, the enemy's deployment and all changes would be clearly visible. It was simply like using a cheat, wasn't it?

He refused Hu Shouren and his brother's advice to go to the sky for him, and under the worried gazes of the generals, he personally boarded the hanging basket.

The soldier in charge of taking care of the magic lamp turned the capstan and loosened the rope at the same time, and the balloon slowly rose into the air under the support of the hot air.

"The Marshal has ascended to heaven!" Seeing this magical scene, the soldiers in and out of the city exclaimed in amazement. Many of them knelt on the ground and worshiped him, and their loyalty to the Marshal increased.

As the altitude continued to rise, Xifengkou Pass and the long border wall gradually fell under Qi Jiguang's feet. The mountains became an undulating yellow picture scroll, which was in his sight.

Although it was not his first time to go to the sky, Qi Jiguang was still extremely shocked. The feeling of having everything under your feet was really intoxicating.

"Looking from the side, I see a mountain, and looking from the side, I see a peak, all because I am in this mountain." Qi Jiguang sighed softly, feeling that his whole realm had been sublimated. The cold wind blew the balloon violently, and he came to his senses and quickly tied the cloth belt in the hanging basket tightly around his waist to prevent any accidents.

Then Qi Jiguang took out the precious brass-shell binoculars from his arms.

At present, his craftsmen can already imitate monocular telescopes, but the quantity is limited and the quality is not up to standard. It is still far behind the batch Zhao Hao gave him. As for binoculars, they still can't make a single one, let alone this clear and high-power telescope.

The biting cold wind caused the balloon to shake violently. Qi Jiguang took great effort to steady himself and looked toward the north through the telescope.

The land was desolate, and the mountains and rivers turned into patterns, corresponding to the map in his mind. After searching for a long time, he finally saw the rising dust in the north. Looking down along the dust, he could vaguely see a black line along the Leopard River moving very slowly to the south.

He knew that it was the Tartar army, and it would probably take another two days to get here.

Qi Jiguang moved the telescope and continued to observe, but he found no trace of large troops on several other routes that the Tartars might have invaded.

When the hot air balloon stopped rising, he could even see Shanhaiguan and the sea more than 200 miles away, but he still did not see any new enemies.

Qi Jiguang felt relieved. It seemed that just as he had guessed, the Tatars would not divide their troops this time. Instead, the various Uriankhai tribes gathered together and headed towards Xifengkou.

This is easy to understand. The Tartars always divided their troops before because the border wall was riddled with holes and they could come and go freely. Dividing the troops could improve the efficiency of robbery. Now that the border wall is solid and heavily guarded, of course they have to concentrate their superior forces and go all out to dig a hole. After that, they have to guard the way out. Wouldn't it be too stupid to divide the troops again?

Qi Jiguang carefully put the telescope back in his arms and leaned over to look at the Xifengkou area below him, but his eyes were not on the city wall. The city wall had three high walls, more than two meters high, and six hollow watchtowers that supported each other. Even thousands of troops could not break through, not to mention that the Mongols were not good at attacking cities.

So he estimated that Dong Huli would choose to break through one or several of the passes such as Dongjiakou and Shijiayu on the west side of Xifengkou.

Then how to deploy the troops becomes obvious.