The Jin Dynasty had developed an alliance…

Later Liang, a state of the Sixteen Kingdoms, is founded in 386 by the Lü family of the Di ethnicity.

All rulers of the Later Liang will proclaim themselves "Heavenly Prince" (Tian Wang).

Huiyuan, a Mahayana Buddhist theologian, establishes the cult of Pure Land Buddhism in China, calling it the White Lotus sect.

According to this belief, the cosmos contains many Pure Lands, in each of which dwells one Buddha.

In 386, Huiyuan builds the Donglin Temple (literally "East Wood Temple", a Buddhist monastery approximately twenty kilometers (twelve miles) from present Jiujiang, Jiangxi Province, People's Republic of China.

Built in 386 CE at the foot of Lushan, the temple is today well known for how long it has stood without collapsing.

The defeat of the Former Qin in the Battle of Fei and the subsequent uprisings split its territory into two noncontiguous pieces after the death of Fu Jian: one located at present day Taiyuan, Shanxi, is soon overwhelmed in 386 by the Xianbei under the Later Yan and the Gaoche, or Dingling.

The other portion, occupying greatly reduced territories around the border of present day Shaanxi and Gansu, struggles for survival.

Teng, while on a campaign in 386, commissions Zhai Liao to keep guard of Liyang; instead, Zhai Liao captures Teng and seizes Liyang. (Zhai Liao's rebellion contributes to the suspension of Xie Xuan's campaigns to try to recover northern territories for Jin.)

Jinsa, the younger brother of Chimnyu, had ascended to the throne because the heir, later King Asin, was too young, according to the Samguk Sagi.

According to the Japanese Nihon Shoki, however, he usurped the throne by force.

Jinsa has ordered numerous attacks against Goguryeo, which is expanding into Baekje territory from the north.

In the year 386, he commands all men above the age of fifteen living in Cheongmongnyeong (present-day Kaesong) to move north and west to defend the borders.

He sends the noble Jin Gamo to attack the Goguryeo Dogon Castle, which is conquered.

The increasing strength of the Arians proves a formidable task for Ambrose.

In 385 or 386, the emperor and his mother Justina, along with a considerable number of clergy and laity, especially military, profess Arianism.

They demand the transfer of two churches in Milan, one in the city (the basilica of the Apostles), the other in the suburbs (St. Victor's), to the Arians.

Ambrose refuses and is required to answer for his conduct before the council.

He goes, his eloquence in defense of orthodoxy reportedly overawing the ministers of Emperor Valentinian, so he is permitted to retire without making the surrender of the churches.

Ambrose has introduced popular music into church services.

He builds an important basilica (later known as the Basilica di Sant'Ambrogio) in Milan in 386.

Tuoba Gui, the grandson (or son) of the final Prince of Dai, Tuoba Shiyijian, had reasserted independence by 386, initially with the title of Prince of Dai, and then as the Prince of Wei, and his state is therefore known in history as Northern Wei.

Zhai Liao has repeatedly tried to attack Jin during the past two years, but has been repelled in his efforts, and he apparently enters into an alliance with Western Yan's emperor Murong Yong.

In 387, Murong Chui attacks Zhai Liao, and many of Zhai Liao's subordinates surrender quickly.

Zhai Liao, in fear, agrees to submit to Later Yan, and Murong Chui permits him to remain at his post and creates him the Duke of Henan.

In winter 387, Zhai Liao repudiates allegiance to Later Yan and attacks Later Yan's Qinghe (roughly modern Xingtai, Hebei) and Pingyuan (roughly modern Dezhou, Shandong) prefectures.

Theodosius has resided mainly in Constantinople from the end of 380 to 387, during which time he has taken most of his measures to improve the capital.

The plan for the Forum Tauri, designed after the model of Trajan's Forum in Rome, is outstanding: it is the largest public square known in antiquity.

It is unclear, however, to what extent the Emperor has encouraged the flowering of art and literature in his time.

In international affairs, long-standing negotiations with the Persians over the division of power in Armenia have resulted in a treaty that is to become the basis for a long period of peace on Rome’s eastern border.

The compromise peace with the Persians concluded in 387 gives Rome a small section of Armenia, where the emperor founds Theodosiopolis (Erzurum)

The Persians had been forced by Diocletian to relinquish Armenia, and Tiridates III, the son of Tiridates II, had in about 287 been restored to the throne under Roman protection; his reign had determined the course of much of Armenia's subsequent history, and his conversion by St. Gregory the Illuminator and the adoption of Christianity as the state religion (c. 314) has created a permanent gulf between Armenia and Persia.