Even up to 500 years since the start of the Malayalam calendar which commenced in 825 AD, Malayalam literature remained in preliminary stage. During this time, Malayalam literature consisted mainly of various genres of songs. Ramacharitham written by Cheeramakavi is a collection of poems written at the end of preliminary stage in Malayalam literature's evolution, and is the oldest Malayalam book available. Thunchaththu Ramanujan Ezhuthachan (17th century) is considered as the Father of the Malayalam language , because of his influence on the acceptance of the Malayalam alphabet and his extremely popular poetic works like Adhyathmaramayanam . Several noted works were written during the 19th century, but it was in the 20th century the Malayalam literary movement came to prominence. Malayalam literature flourished under various genres and today it is a fully developed part of Indian literature.