25 events the sources record for this year, grouped by region.
What happened
China (5)
Yi San-bo's report on the movements of the Chinese troops and the timing of their dispatch (Annals of the Joseon Dynasty 宣祖實錄 二十五年 · 宣祖實錄 16책 33권 21장 B면 · 기사 wna_12512017_005)
Bo Bai, a retired deputy commander in Ningxia, killed Governor Dang Xin and others, seized the city and rebelled. (History of Ming (Mingshi), Annals 明史 卷20 萬曆二十年)
Facing Korean warships across the Imjin River, the Japanese feigned retreat to lure the Koreans out and routed them, then crossed with the whole army on captured boats and rafts. (Griffis, Corea, the Hermit Nation p.106)
Hideie and others attacked Korea again and fought the Ming without a decisive result. The overseas campaign lasted seven years in all. (Rai Sanyō, Nihon Gaishi 卷之二十 · part_03 글자위치 1890)
Korean Peninsula (18)
On the 14th the Japanese raise their troops, take Busanjin, and magistrate Jeong Bal and Song Sang-hyeon die in battle (Annals of the Joseon Dynasty 宣祖修正實錄 二十五年 · 宣祖修正實錄 6책 26권 1장 B면 · 기사 wnb_12504014_001)
Enemy troops invade Chungju, and Sin Rip dies in battle (Annals of the Joseon Dynasty 宣祖修正實錄 二十五年 · 宣祖修正實錄 6책 26권 5장 A면 · 기사 wnb_12504014_016)
The troops of the three provinces are defeated at Yongin (Annals of the Joseon Dynasty 宣祖修正實錄 二十五年 · 宣祖修正實錄 6책 26권 13장 A면 · 기사 wnb_12506001_001)
Gyeongsang Right Governor Kim Seong-il's memorial reports on the battle situation in Gyeongsang Province (Annals of the Joseon Dynasty 宣祖實錄 二十五年 · 宣祖實錄 16책 33권 5장 B면 · 기사 wna_12512005_004)
Japan invaded Joseon and took the royal capital; the Joseon king Seonjo fled to Uiju and asked for help (Imjin War). (History of Ming (Mingshi), Annals 明史 卷20 萬曆二十年)
On May 25 the Japanese fleet (Konishi's force) landed at Busan, took the town and besieged Dongnae Fortress, which soon surrendered. (Griffis, Corea, the Hermit Nation p.100-101 (ch.XIII))
Konishi's force left Dongnae and marched north to Sangju along the Nakdong River. The Busan magistrate went to Seoul but falsely reported that he had not delivered the letter. (Griffis, Corea, the Hermit Nation p.101 (ch.XIII))
Konishi's army besieged and took Chungju Fortress after several days. Citing Frois's report, of 5,000 Korean losses, 3,000 died at Chungju. (Griffis, Corea, the Hermit Nation p.102-103)
Kato's and Konishi's forces entered Seoul on the same day. The king, court and army had left the capital three days earlier, so there was no resistance. (Griffis, Corea, the Hermit Nation p.103)
Japanese land and naval forces assembled at Nagoya in Hizen (present-day Karatsu). Figures in the source: of 500,000 mobilized, 150,000 for the invasion, 60,000 in reserve, 100,000 guarding Hideyoshi. (Griffis, Corea, the Hermit Nation p.96 (ch.XIII The Invasion-On to Seoul))
Sub-Saharan Africa (1)
The embassy sent by Qadi Umar leaves Timbuktu and goes with the Shaykh to the Sultan of Marrakesh (Tarikh al-Sudan (Chronicle of the Sudan) Houdas 1900 불역 장 XXI-XXIII (houdas1900_fr_djvu.txt 줄 11631))