Sant Dnyaneshwar lived in Maharashtra from 1275 to 1296. He wrote a Marathi translation of Bhagawat Gita, to make it available to common man of that time. It is popularly known as Dnyaneshwari. 

Sant Dnyaneshwar took  Samadhi at an early age of 21 in Alandi. 

Wiki Article   describes Sant Dnyaneshwar very well. Another good article is here.

He and his 4 siblings went through troubled childhood due to non-acceptance of his family from Brahmins for his fathers change from Sanyasashram to Gruhasthashram. The Siblings were sparkling in their knowledge and at such young age described Advaita to the people in the language they could understand.

Sant Dnyaneshwar combined gyan and bhakti – knowledge and devotion. Lakhs of devotees travel from Paithan to Alandi every year singing devotional songs, and dancing and getting immersed in the divine.