On June 21, the 20th Army, the attack force on the northern flank of the expeditionary force, finally came out of Gaoli Mountain.

The siege of Tengchong began.

Tengchong, a beautiful border city on the Sino-Myanmar border west of the Hengduan Mountains.

It connects Baoshan and Dali in the east, Myanmar and India in the west, Pianma and Lushui in the north, Longling and Mangshi in the south, and connects with Yunnan and Myanmar in the south, like an emerald inlaid in the jungle of Wanshan.

It is the largest political, economic and cultural center on the border between China and Myanmar, and is known as "the birthplace of modern industry and commerce in Yunnan" and "the window of Southeast Asia, South Asia and Western Regions culture". During the Tang Dynasty, Tengchong Mansion was established here, and after the Yuan Dynasty, the central government of each generation successively set up divisions, prefectures, provinces, departments, bureaus, etc., these institutions, equivalent to the current regional level, are second only to the provincial settings.

This is an extremely prosperous commercial town. The famous Southern Ancient Silk Road extends here, it crosses the Hengduan Mountains, winds from Chinese mainland, and passes through the city to Southeast Asia, South Asia, and West Asia, known as the "Bonan Ancient Road". In terms of time, it predates the famous Northern Silk Road, which traverses the desert, by more than 200 years.

"Tengyue Prefecture Chronicles" notes: "Tengyue lives outside the world, the land is vast and the soil is fertile...... Eighteen provinces gathered. "It entered its heyday during the Qin and Han dynasties, and slowly declined after the Tang and Song dynasties. In 1899, the British set up a consulate here, and in 1902, the Qing Dynasty began to set up customs in Tengchong, and even Kunming Customs was under the subordinate of Tengchong Customs at that time.

The construction of Tengchong City is also very peculiar, it is the only ancient city built of stone in China.

The city is square, the wall is two zhang five high, one zhang eight thick, all are made of huge stone masonry, the construction is unusually solid, the city wall design is ingenious, the stone city buttress is built on it, both can peep outward, and can be defended, the city chief is three points, set up 4 city gates in the southeast and northwest, the gatehouse is several feet higher than the city wall, it is about twice as thick as the city wall, it is majestic and majestic, it is magnificent.

Tengchong is a stone city that was built during the orthodox years of the Ming Dynasty, and after nearly 500 years of wind and rain, it is still as solid as a rock.

The famous traveler Xu Xiake admired Tengchong's gorgeous scenery, bustling streets, and profound culture: there is no other place in the West! Hence the name "The First City on the Far Side".

Heading west, along the rugged "Bonan Ancient Road", it only takes more than 200 kilometers to reach Myitkyina, an important town in northern Myanmar. When the Yunnan-Burma Highway was blocked, General Stilwell of the United States had to open another Chinese mainland external communication line, and he first considered the Sino-Indian Highway, and he outlined a red line from India's Ledo through Myanmar's New Pingyang to Myitkyina, and then to China's Myanmar Boundary Pillar 37 to Tengchong, and incorporated measures to achieve this red line into the meticulous "Tarzan of the Apes" plan.

After the 100,000 Chinese Expeditionary Force lost its first invasion of Burma, it was forced to retreat along the Yunnan-Burma Highway to China through western Yunnan. Previously, Tengchong, as the rear of the expeditionary force, was far away from the battlefield, and according to the meaning of the high-level of the national army, the Japanese army would not hit here, so not many troops were stationed there. However, no one expected the situation to deteriorate suddenly, and the Japanese army followed the retreating expeditionary force into western Yunnan, and finally blew up the Huitong Bridge before blocking the Japanese army on the west bank of the Nu River.

After the Japanese army occupied the Longling area, it could not cross the Nu River for a while, so it expanded its results and sent troops to Tengchong. At this time, the local Chinese armed forces stationed in the Tengchong area were in charge of Long Yun's son, Long Shenwu. After receiving the news of the Japanese army's advance, Long Shenwu kept it a secret, stepped up the rush to transport relatives and property, and fled to Kunming.

The next night, Qiu Tianpei, the county magistrate, also absconded with the Self-Defense Forces and police. The dragons were leaderless, the soldiers were scattered, and only the unarmed people remained, and the Tengchong people fled one after another, leaving an empty city. Three days later, a mere 292 Japanese soldiers drove straight into Tengchong without firing a single shot, occupying this "first border city on the extreme border" that had stood for 500 years.

......

At the end of 1943, construction of the China-India Highway began.

At that time, a huge construction highway unit composed of 5 U.S. mechanized chemical corps, 1 black artificial barracks, 2 Chinese engineering regiments and local migrant workers took to the road, and the roar of large road construction machinery sounded in the uninhabited Savage Mountain.

After the failure of the first invasion of Burma, Savage Mountain had been brought under the control of the Japanese army, and in order to remove the obstacles at that time, General Sun Liren led the Chinese army in India as the pioneer, all the way to Myitkyina.

On May 17, 1944, heavy gunfire rang out at Myitkyina West Airport, and the battle for Myitkyina began.

Masaki Honda, the new commander of the 33rd Army of the Japanese Army, which had been organized at the end of April, had just taken over the defense of northern Burma and western Yunnan when he heard deafening gunfire.

This Myitkyina is "the key point of Sino-Indian land transport in northern Burma", and it is also an important base of the Japanese army in northern Burma, if Myitkyina is lost, it will be difficult to hold on to northern Burma. Honda was overwhelmed with political materials and rushed to the front line to directly direct the war in Myitkyina.

At this time, the Japanese Southern Army had already carried a heavy burden for its "Operation U", and the 80,000 Japanese troops on the Imphal Heights were caught inside and outside by the British army, and all of them were firmly pinned down and unable to move. It was already impossible to count on reinforcements from there, and Honda Masato had no choice but to mobilize his own 33rd Army to save Myitkyina.

In order to keep this important land, he hurriedly transferred troops from northern Burma and western Yunnan to reinforce Myitkyina, although the commander of the 56th Division at that time, Major General Sakaguchi, repeatedly complained to him because of the lack of troops, then he still quickly transferred the troops under the command of the 1st Brigade of the 148th Wing of the 56th Division and the commander of the infantry regiment of the 56th Division, Mizumi Genzang, to Myitkyina.

As a result, Matsuyama Sakaguchi's defense forces in western Yunnan were even smaller.

At this time, Honda Masasai also assumed the responsibility of the defense of western Yunnan, and at the time of fully coping with the situation in northern Burma, he must always open his other eye and stare vigilantly at western Yunnan, he has only one division stationed on the west bank of the Nu River, and this division that he has drawn and transferred nearly two brigades of troops will face nearly 10 troops of the Chinese Expeditionary Force.

For northern Burma, western Yunnan is its back, and for Myitkyina, which is fighting fiercely, Tengchong is its back, if Tengchong is broken through by the Chinese army, then Myitkyina will soon be unable to hold on, if western Yunnan is broken through, northern Myanmar will also be finished soon.

On April 13, 1944, when the Chongqing Military Commission issued the "Nujiang Attack Order", it clearly instructed: "Plan for the Indian army to attack Myitkyina and open the Sino-Indian highway." The expeditionary force was aimed at Myitkyina's "weak back" Tengchong.

With this special geography, the "First City on the Extreme Side" has naturally become the first target of the counteroffensive in western Yunnan!