Of course, this is only the minimum age allowed for marriage by law, and except for the Shengdou Xiaomin, who are eager to import Dingding, the children of the nobles of the Tang Dynasty generally do not marry so early.

Wang Fei remembers that before the crossing, he had read an academic article on the Internet that looked at the marriage age of the Tang people. By combing through a large number of cases recorded in historical materials and analyzing them quantitatively, this paper concludes that during the reign of Xuanzong, the average age of marriage for men and women was 22 and 17 years old respectively. And Wang Yong is 25 years old this year, but he is not married.

For Su Sanniang, who has a hearty personality, superb swordsmanship and has repeatedly rescued him, Wang Fei has always had respect. If Wang Yong and Su Sanniang tied the knot, of course he would raise his hands in favor.

Thinking that Wang Yong might be "haggard for Yixiao", Wang Fei repeatedly encouraged Ashina Wenxia to join forces with himself to promote good things together.

Helplessly, although Ashina Wenxia dared to make Wang Yong's jokes, she was very in awe of her master, Su Sanniang. Regarding Wang Fei's proposal, she just stuck out her tongue, saying that she couldn't help.

When Wang Fei was still thinking about how to help Wang Yong create opportunities, he overheard him ask about "mountain fortification", and suddenly realized: "Uncle Wang Yong, are you worried about the battle of Stone Fort!" ”

"Although the little lady Yiyue is extraordinary, she can't compare to Xiao Langjun's natural wisdom!" Wang Yong smiled helplessly, and then explained: "There are three or two old friends under the command of Brother Shuhan, the envoy of Longyou Jiedu, and the battle to capture the stone castle is about to begin, and I am worried that the old friend will be lost, so I am worried. ”

For the battle of Stone Castle, which has left a strong mark in the history of the Tang Dynasty, Wang Fei knew something before he crossed over. He was deeply impressed by the steep terrain of the stone fort, the hardships of the Tang army's bloody battle, and the disparity in losses between the two sides.

At that time, Wang Fei also conducted a war game with a group of Tang history enthusiasts on the Internet to discuss whether the Tang army could capture Shibao City at a smaller cost.

In the exercise, everyone found that no matter how the Tang army changed and adjusted its offensive strategy, the Tubo defenders only needed to firmly hold the sheep intestine trail in the mountains to respond to all changes, and the Tang army attacking on the back could only rely on human lives to consume the rolling stones and trees of the Tubo army. As long as the Tibetan army's fortification equipment was not exhausted, it would be impossible for the Tang army to attack the stone fort......

When the conventional tactics were completely hopeless, some people opened their brains and proposed to travel back to the Tang Dynasty, develop hot air balloons, paragliders and other sharp weapons, and capture Shibao City with divine soldiers from the sky.

But this plan was immediately rejected. Not to mention whether hot air balloons and paragliders could be made with the technological level of the Tang Dynasty. Even if it could be made, how much of a role would a hot air balloon that lacked power drive and could only be used to get on and off the stone castle in the Battle of Stone Castle? I'm afraid that the function of spiritual deterrence is far greater than the actual effect.

As for the idea of flying into the stone castle from a high place with a paraglider, it is also purely fantastical. The stone fort was not built on a plain or the bottom of a valley, but on one of the highest peaks in Chiling, so how could it be soaring into it? Even if you can find a mountain peak higher than Shibao City, the turbulent air flow between the lofty mountains and mountains will bury the Tang soldiers gliding down.

After deducing for a long time, everyone finally reached an agreement: unless the scientific and technological strength of the Tang army advances by leaps and bounds or the domestic political pattern of Tibet changes fundamentally, otherwise, the battle of Shibao in the eight years of Tianbao, the best outcome of the Tang army can only be to step on the white bones of thousands of soldiers and reap a crushing victory.

"Geshuhan has done his best to do his best!" When someone on the Internet was so emotional, a divine reply appeared under the post that Wang Fei remembered: "If Ge Shuhan, who has achieved ten thousand things, has done his best, wouldn't Wang Zhonghe, who would rather sacrifice glory and wealth than consume the lives of Tang Army soldiers in vain, be more selfless and greater?!" ”

After the crossing, although Wang Fei was in the Beiting Protectorate, while thinking about how to reverse the battle of Talas, he also repeatedly calculated the battle of the stone fort.

On the basis of a more intuitive understanding of the Tang army's combat strength and equipment level, Wang Fei sadly found that no matter how he deduced, if he wanted to storm the stone fort when Tubo was on full alert, only by squeezing out the last drop of blood of the Tang soldiers and using the red blood enough to stain Qinghai as a weight, it was possible to exchange for a bloody victory on the other side of the scales.

Because he was worried that his thoughts were not thorough, after the Western Expedition was determined and before the Yuanxi fire, Wang Fei also quietly talked to Du Huan about how to reduce the casualties of the soldiers when attacking the stone fort.

After hearing Wang Fei's worries, Du Huan immediately found the map, and his emaciated fingers dotted the drawings around, as if he hoped to find a shortcut to victory in the thousands of hills and ravines.

After pondering for a long time, Du Huancai shook his head and sighed: "Xiao Langjun, a certain talent is shallow in learning, and he really can't get the best of both worlds between saving the lives of soldiers and capturing the stone castle. Xiao Langjun might as well discuss with Du Hu, and if you want to come to Du Hu's eloquence, you should have a high opinion. ”

And after Wang Zheng saw the intention of his young son, he reluctantly took Wang Fei to his study with a wry smile.

Wang Fei has been to the study several times, but at this time he can't help but have some doubts, I don't know why his father took him to the study solemnly.

In the Tang Dynasty, the study of officials was generally a private place for their self-cultivation, thinking about government affairs, and receiving close friends, and its importance was second only to that of the official room. Therefore, if there is no urgent matter or the call of his father, Wang Fei rarely sets foot here.

After entering the study, Wang Fei was once again shocked by the mountain of papers in it.

Wang Zhengjian was born in the long house of the Wang family in Taiyuan, and was a child of a family full of poetry and books, so his study was different from the "study" of many border commanders and military generals, and it was not used to decorate the façade.

In the large study room, neatly arranged on several rows of bookshelves, all kinds of books are placed in different categories. This situation reminded Wang Fei of the familiar university library.

Wang Zhengjian came to a row of bookshelves and reached out. Wang Fei thought that his father was searching for some file or information, but he saw the bookshelf spin open, revealing a secret door hidden behind it.

Wang Fei was stunned, and Wang Zheng saw that he had already lit the lamps and candles in the secret room. Under the dim light, a huge sand table attracted Wang Fei's attention.

At the beginning of Wang Fei's crossing, he naively listed the sand table in the list of "golden fingers". But soon, he discovered the naivety and ridiculousness of this idea.

First of all, the basis of modern sand tables is not plastics and models, but advanced and sophisticated measurement technology. Without modern measurement technology, the importance of simply inventing the sand table was greatly reduced.

Secondly, ancient China was not without sand tables. According to historical records, Ma Yuan, a general of Fubo in the Eastern Han Dynasty, once "gathered rice for the valley and pointed to the situation." That is, the battlefield terrain was piled up with grain, and the mountains, highlands, plains, rivers, canyons, important places, passes, cities, roads, and the layout of the armies on both sides were marked with various colored beans. Of course, in the absence of effective measurement methods, this simple sand table can only reflect the terrain of a very narrow space, but cannot show the topography of a wide area.

In the official office of the Beiting Metropolitan Protectorate, there is a huge sand table, which clearly shows the terrain and landform near Tingzhou City. However, as far as Wang Fei knows, due to the constraints of surveying and mapping methods, there is no large sand table in the Beiting Metropolitan Protectorate that reflects the geography of the entire moraine.

The sand table in front of Wang Fei is a military regional campaign sand table that has been improved on the basis of the Han Dynasty sand table.

Wang Zhengjian didn't say a word, and let Wang Fei carefully study the terrain and landform shown in the sand table with the help of lights.

Wang Fei originally thought that the content of the sand table was the mountains and rivers of the Western Regions, and his father hid it in order to keep it secret. But he only looked at it for a moment, and he knew that the sand table was definitely not the terrain of the area under the jurisdiction of the Beiting Metropolitan Protectorate, because the mountains in the sand table were dense and the flat land was narrow, and there was no trace of any basin.

Where exactly is the terrain? Wang Fei stared at it for a long time, and then carefully compared the satellite map in his memory, and was surprised to find that the sand table demonstrated actually the mountains and lakes with Shibao City as the center, including Chiling and Qinghai.

"Fei'er, do you understand?" Wang Zhengjian's tone was a little gloomy.

"Father, why are you so concerned about the war in Longyou?" Wang Fei was slightly puzzled. The goal of the Beiting Jiedu envoy is to prevent the Hui Hui, the Huangjia and the Tuqishi, while the Longyou Jiedu envoy is to prepare for the northward advance of Tubo, and the strategic tasks of the two can be said to be no overlap.

Wang Zhengjian stared at the young son's immature face for a long time with solemn eyes, and then sighed faintly: "Fei'er, this sand table is not a certain thing, but an old friend is stored here. He had been thinking hard day and night about how to suppress the Tibetan in Chiling and Qinghai, so he walked all over the mountains and rivers around the stone fort, and painstakingly made this giant sand table. ”

"Then does he have a solution to the battle for the Stone Castle?" Wang Fei saw that his father only mentioned "old friends" and did not mention their names, so he wisely did not ask who the sand table was.

"Yes!" Wang Zheng saw that his eyes were shining, and he said categorically. Elegant, he suddenly exuded a strong and complex momentum. Among them, there is not only the confidence of looking down on the world, but also the anger of the trapped beast in the cage......

It was the first time Wang Fei had seen his father have such strong emotional fluctuations, and he couldn't help but be more curious about the identity of the owner of the sand table.

"Give up the competition for the stone fort, or go out of the Dadou Valley from the west, or go out of the stone mountain in the south of Longnan from the east, bypass the Chiling natural danger, ambush the city in the west, attack the land of Jiuqu in the east, transport troops between the mountains and rivers in the east and west, give full play to the advantages of our army's strong strength and complete equipment, open up in the field, build cities and consolidate the borders, fight for each step, gradually retract, continue to consume the strength of Tubo, and then recapture the original Tuguhun land from Tubo! When Qilian Mountain, Fu Qi City, Jiuqu Land, and Jishi Mountain are all in my hands, just a stone fort, you can go down without a fight! In this way, with my strength, we can attack the enemy's short, accumulate sand into a tower, and constantly weaken the strength of Tibet, which can be as long as ten years and as short as seven or eight years, and then we can cut down the grass and eradicate the roots, and drive the northbound Tubo back to its old nest. After the retreat of Tubo, a new section of envoys can be built in Tuyuhun's hometown to lead the armies, and the descendants of Tuyuhun can be used as a buffer to defend Tubo from advancing northward. In this way, there are no more military disasters in Longyou, and there are no worries about the hinterland of Guanzhong. ”