I found this very helpful timeline on Douban. This is not an exact translation but a summary with some edits or clarifications from my own notes. Wherever my notes don't match with the Douban post, I went with the Douban post.

https://www.douban.com/group/topic/494110496/?_spm_id=MTg4MTA4OTI1&_i=4214871C5ObpxO

25 Years Ago · Northern Qin

• Mu Lianying/Shao Ying/Yuan Xiaoliu a descendent of Mulian Right Wise King was in love with Shao Yang but Shao Yang was summoned to the palace by imperial edict, forcing them apart.

• Shao Yang became pregnant with the Northern Qin Emperor's child. For the child's sake, she advised the Northern Qin emperor to eliminate the Right Wise King's lineage— Mu Lianying survived by chance.

25 Years Ago · DaYe · Shangjing (the old DaYe capital; now Northern Qin territory)

• Grand Tutor Xie and Consort An (a concubine of Emperor Wenxi) secretly had an affair and had a son (Li Mao). They covered it up by unknown means (suspected to be swapping him with the eldest son of the late Prince of Qi).

• The An and Lu clans' treason case (colluding with the Northern Qin Right Wise King Mu Lian's lineage) – the An and Lu clans were executed at Hongyan Pavilion.

24 Years Ago · Daye · Shangjing (now Northern Qin territory)

• Princess Yunzhao defied an imperial edict to marry Grand Tutor Xie.

• Emperor Wenxi died in battle.

• The Cui clan submitted a secret memorial requesting Empress Wenxi to order the remaining imperial guards to escort the noble families south. Empress Wenxi remained alone in Shangjing.

• Empress Wenxi forged the Que Gu (Sparrow Bone/Phoenix Token) command token, dividing it into four pieces entrusted to four confidants (Liu Yu'e, Xiao Ju, Princess Yunzhao, Cui Jun), then died.

• Empress Wenxi's senior palace maid Liu Yu'e, along with several imperial shadow agents, fled with one-quarter of the Que Gu token, escorting Crown Prince Wenxi.

• With the fall of the capital, all of Emperor Wenxi's lineage except for Crown Prince Wenxi were either killed or captured. The noble families fled south, electing a member of a distant branch of the Li clan as new emperor, establishing Nanye, with its capital at Jiangkang.

• Liu Yu'e met with Xiao Ju. Xiao Ju sacrificed his second son Xiao Sheng to give Crown Prince Wenxi a new identity.

16 Years Ago · Jiankang

• Xie Jiayu's parents were killed by Northern Qin people. She was taken in by an orphanage and later brought back by the Princess Yunzhao, who raised her as her own child.

10 Years Ago · Qizhou

• Northern Qin attacked; Qizhou fell. The late Prince of Qi and his consort died, and their children Li Mao and Li Lejun fled.

10 Years Ago · Somewhere on the way from Shangjing to Jiankang

• The Xiao family encountered pursuers. Xiao Yao was injured while protecting Xiao Sheng, leaving his left leg disabled. The Princess-consort broke down and revealed Xiao Sheng's true identity.

• Liu Yu'e and Xiao Ju presented the Que Gu token. Crown Prince Wenxi chose his own courtesy name: Wu Yi (meaning "without clothes").

10 Ago · Somewhere on the way from Qizhou to Jiankang

• Xiao Wuyi rescued Li Mao and Li Lejun and escorted them back to Jiankang.

10 Years Ago · Jiankang

• Li Mao became Prince of Qi; Li Lejun became Pingning County Princess. They established the Qi Prince's manor.

• Li Mao studied under Grand Tutor Xie. Princess Yunzhao treated Li Lejun's illness.

10 Years Ago · Beifu

• Xiao Wuyi joined the military and began establishing the Northern Garrison (Beifu) .

5 Years Ago · Jiankang

• The He clan poisoned the Emperor and placed Consort He's son on the throne.

• The new Emperor's position was unstable. Coinciding with a shortage of supplies for the Beifu Army, Empress Dowager He agreed to supply provisions to Xiao Wuyi on the condition that he marry a woman from the He clan. He agreed.

• He Yuanji's lover Pei Runheng was killed (or fake killed) by the Empress Dowager's men. Xiao Wuyi sent men to find Pei Runheng to inform him of the truth behind the arranged marriage, but they were too late. He Yuanji married into the Jing'an Prince's manor. Xiao Wuyi did not return. The Beifu Army achieved a major victory on the front lines (recapturing the He clan's homeland).

1 Month Ago

• Grand Tutor Xie orchestrated a scheme to guide Xie Jiayu into designing a repeating crossbow. The Empress Dowager obtained the blueprints and, through the Prince of Changsha, had the crossbows mass-produced and sent to the Jiuzhangyuan front line. Thirty thousand Beifu soldiers died as a result.

• Empty fort strategy - Xiao Wuyi used himself as bait to lure the Eagle King's forces into the city, setting fire to Jiuzhangyuan and winning against overwhelming odds. However, he was injured—intracranial hemorrhage causing optic nerve compression, leading to intermittent blindness. His life is now in jeopardy.

Unknown Time (Approximately 5 Years Ago)

• Xiao Wuyi's deputy general Duan Ying died defending Yuezhou (one of the three prefectures Xiao Wuyi won back in Episode 10 via the "horseback archery" challenge). His widow Ruisheng, then a military physician, was captured by enemy forces after the city fell. One month later, Xiao Wuyi rescued her. Ruisheng discovered she was pregnant. Her husband's family and her own family questioned her chastity and wanted to force her to be buried alive with her husband (a traditional殉葬 practice). Xiao Wuyi saved and protected her by claiming her as his own (under the pretense of "taking by force"). To stay closer to where her husband died, Ruisheng chose to remain with the army.

Thank you! very helpful :)