Sachchidananda Hirananda Vatsyayan, popularly known by his pen name Agyeya, was an Indian writer, poet, novelist, literary critic, journalist, translator and revolutionary in Hindi language. He pioneered modern trends in Hindi poetry, as well as in fiction, criticism and journalism. He is regarded as the pioneer of the Prayogavaad (experimentalism) movement in modern Hindi literature.

Hindi literature includes literature in the various Hindi languages which have different writing systems. Earliest forms of Hindi literature are attested in poetry of Apabhraṃśa like Awadhi, and Marwari languages. Hindi literature is composed in three broad styles- गद्य (Gadya-prose), पद्य( Padya- poetry) and चम्प्पू In terms of historical development, it is broadly classified into five prominent forms (genres) based on the date of production. They are:Ādi Kāl /Vīr-Gāthā Kāl -- [prior to & including 14th century CE.] This period was marked by Poems extolling brave warriors. Bhakti Kāl --[14th–18th century CE.] Prominent genre in this period was Poems of Devotion due to Bhakti Movement. Rīti Kāl /Śṛṅgār Kāl -- [18th–20th century CE.] The major genre of this period is Poems of Romance which are marked with high ornamentalism. Ādhunik Kāl -- [from 1850 CE onwards.] Literally means Modern literature. Navyottar Kāl -- [from 1980 CE onwards.] Literally means Post- Modern literature.