Kokinshū

The Kokin Wakashū (古今和歌集^?, "Collection of Japanese Poems of Ancient and Modern Times"), commonly abbreviated as Kokinshū (古今集^?), is an early anthology of the waka form of Japanese poetry, dating from the Heian period. It is an Imperial anthology, conceived of by Emperor Uda (r. 887–897) and published by order of his son Emperor Daigo (r. 897–930), in about 905. Its finished form dates to c. 920, though according to several historical accounts the last poem was added to the collection in 914. The compilers of the anthology were four court poets, led by Ki no Tsurayuki and also including Ki no Tomonori (who died before its completion), Ōshikōchi no Mitsune, and Mibu no Tadamine.

The Kokinshū is the first of the Nijūichidaishū (二十一代集^?), the 21 collections of Japanese poetry compiled at Imperial request. It was the most influential realization of the ideas of poetry at the time, dictating the form and format of Japanese poetry until the late nineteenth century; it was the first anthology to divide itself into seasonal and love poems. The primacy of poems about the seasons pioneered by the Kokinshū continues even today in the haiku tradition.

...
Wikipedia