First of all, the sources are mainly the emperor's records in the Book of Jin, the personal biography of the person concerned, and the Zizhi Tongjian.

I won't write about the "Three Thousand Righteous Servants" and "More than Thousand Rides" mentioned in other lower-level historical materials, so I'll use these two books.

(1) The second year of Yongjia (308)

"Zizhi Tongjian" "Zhang Liang also sent to supervise and protect Beigong Chun's generals to guard the Beijing Division", "Beigong Chun recruited more than 100 warriors to burst into Chen, and the soldiers were defeated".

The original account contains only these two sentences.

From here, it can be judged that the number of reinforcements in Liangzhou is 100+ (in fact, the warriors recruited by Beigong are not necessarily from Liangzhou...... ）

The circumstances of this battle, as described in the book:

From the analysis of historical records, Wang Mijun should be based on the south of the city and the east of the city, because there are only three times when the place name appears, the first time is in Jinyangmen (south of the city), the second time is in Jianchunmen (east of the city), and the third time is in Qilijian (east of the city).

The history books are vague about the battle process, and there are too many missing, but they are confirmed by many parties, and a general analysis can vaguely show a few points:

(1) The first battle was at Jinyang Gate in the south of the city, and Beigong Chun led more than 100 people to break through the battle, and the "Mi soldiers were defeated" (the main general was not necessarily Wang Mi).

(2) A few days later, the second battle, located in Jianchun Gate, whether there is a history book that does not say, only Wang Mi burned Jianchun Gate and left, I think there is a high probability that it was fought.

(3) After burning Jianchun Gate, Wang Mi retreated to the back (east), and was caught up by the forbidden army at Qilijian and was defeated again.

(4) Synthesizing these records, Wang Mi did not have many people think that more than 100 people broke through the battle and fled, in fact, there was more than one battle, but the historical materials of the Jin Dynasty were seriously blank, the records were incomplete, and the language was not clear, I think at least two battles were fought, and after seeing that there was no hope of victory, he was desperate to die, and then he was pursued by the forbidden army Wang Bingbu, and was defeated in the Qilijian in the east of Luoyang City.

Let's take a look at the direction of the Xiongnu.

In January 308, Liu Yuan "sent ten generals such as the general Cong of the Fu army to the south according to Taihang, and ten generals such as Shi Le, the general of the auxiliary Han Dynasty, went east to Zhao and Wei" - this was to prevent the Jin army from besieging Wei and saving Zhao, so he blocked the Taihang Pass in advance and concentrated on attacking Pingyang and Hedong two counties.

"Beigong Chun and others fought with Han Liu Cong in Hedong and were defeated" - "Zizhi Tongjian".

The "Hedong" here is most likely Hedong County, and it is also in line with the previous Liu Yuan sent Liu Cong to send troops to occupy Taihang.

Liu Cong has a lot of soldiers, and there are a large number of Hun cavalry, so it is impossible for Beigong to have a small number of pure troops.

100+, 1000+ troops are impossible at all, at least thousands.

(2) Yongjia three years (309)

In August of that year, the Xiongnu went south to Luoyang and were defeated at Hongnong.

In October, he went to Luoyang for the second time, and "more than 1,000 night warriors such as Beigong Chun attacked Hanbi and beheaded the general Hu Yanhao." ”

In fact, it is not said here whether these more than 1,000 people are Liangzhou soldiers or not, let's think that it is, the number of people who appeared: 1000+

But it is not said how many Liangzhou soldiers were in Luoyang in 309.

Let's take a look at a few more historical sources:

"The Biography of Zhang Rail": "In the middle of the dispatch, Zhang Lang sent 5,000 volunteers and the county to show filial piety and tribute, and the objects of the instrument party were returned to the Beijing division. Ling Yousi can deduce that Lizhou has come to Qing Zhen Desu, and Jia Dun will be honored: "Highly talented and master's students, writing scriptures and history; martyrdom in danger, killing as a king; Loyalty and infant trouble, dedication and relief; The right to be wise and courageous, to eliminate difficulties in time; misled the lord and injured the loyal and virtuous; Smell it. The fathers and elders in the state are all celebrating. Guanglu Fu Yi and Taichang Zhiyu left a letter to tell the Beijing division that they were hungry, and they immediately sent Du Xun to join the army to sacrifice 500 horses and 30,000 blankets. The emperor sent envoys to worship the general of Zhenxi, the military governor of Longyou, the marquis of the city, and the general of the chariot and cavalry, the opening of the mansion and the three divisions of Yitong. ”

When did Emperor Huai of Jin add General Zhang Rail Zhenxi? October of the fourth year of Yongjia (310).

"Zizhi Tongjian": "Zhao Jia Zhang Liang Zhenxi general, the governor of Longyou military. Guanglu Doctor Fu Yi and Taichang Zhiyu sent a letter to tell the Beijing master that he was hungry. Du Xun donated 500 horses and 30,000 cloths. ”

In other words, before October 310, at least 5,000 Liangzhou "volunteers" had come to Luoyang.

Along with them, there are also official recommendation letters from Liangzhou talents.

There is a high probability that these 5,000 volunteers came in 309 years, and they went back after fighting the Huns.

Zhang Liang sent a letter of recommendation, and there is a high probability that it will be in 309.

After the fight in 309, he may go back in the first half of 310 at the latest.

In October of that year, the Son of Heaven sent an envoy to Liangzhou and crowned Zhang Liang as the general of Zhenxi, which was basically the case.

Why?

"The Biography of Zhang Rail": "Before the strategy arrived, Wang Mi forced Luoyang, and sent the generals Zhang Fei, Beigong Chun, Guo Fu and others to lead 5,000 elite cavalry to defend Kyoto. ”

In October 310, the aforementioned Son of Heaven sent an envoy to Liangzhou to canonize him, but before he arrived, the Xiongnu came to Luoyang again (311).

So Zhang Liang sent "5,000 elite horsemen" to aid the Beijing Division.

It is unlikely that he will send two waves of reinforcements to Luoyang at the same time, after all, the situation in Liangzhou is also complicated.

To sum up–

For the first time (308), Beigong Chun even went to Hedong to fight the Xiongnu Liu Cong and defeated him.

This year's troops, it is impossible to only have 100+, probably a few thousand.

It's not clear when to leave.

The second time (309), there is a high probability that it is the "five thousand volunteers", and it is not clear when they left, probably the end of 309 or the first half of 310.

The third time (311), "Five Thousand Elite Horsemen".

Above.