21 events the sources record for this year, grouped by region.
What happened
China (19)
In the sixth month, Xiao Gui and others fought the Liang army west of Zhongshan but were routed by the rains; Xiao Gui and Li Xiguang died in battle, and only two or three in ten of the survivors returned. (Book of Northern Qi (Bei Qishu), Annals 北齊書 卷4)
In the twelfth month, Western Wei Chancellor Yuwen Jue received the abdication of Wei. (Founding of Northern Zhou; as this is the twelfth lunar month, it falls in the first month of 557 CE.) (Book of Northern Qi (Bei Qishu), Annals 北齊書 卷4)
Xiao Gui and others, with a hundred thousand men, came out of the Zhakou stockade of Qi toward Liangshan; Huang Cong counterattacked and set fire to the vanguard's boats, so Qi halted at Wuhu. (Book of Chen (Chenshu), Annals 陳書 卷1 紹泰2年 三月)
In the decisive battle south of Mofu Mountain, Chen Baxian took the field in person, Hou Andu struck from behind, and the Qi army was crushed; Xu Sihui and his brothers were captured and beheaded, and pursuit reached Linyi. (Book of Chen (Chenshu), Annals 陳書 卷1 紹泰2年 六月)
Xu Sihui and Ren Yue attacked the Caishi garrison, captured Zhang Huaijun, and entered Qi. (Book of Liang (Liangshu), Annals 卷6 太平元年 二月)
Zhou Wenyu and Chen Qian attacked Kuaiji; Zhang Biao, defeated and fleeing, was beheaded by a villager of Ruoye. (Book of Liang (Liangshu), Annals 卷6 太平元年 二月)
Xiao Gui of Qi headed from Zhakou toward Liangshan, and Chen Baxian and Huang Qiu met him and crushed him. (Book of Liang (Liangshu), Annals 卷6 太平元年 三月)