Nazrul's writings are about themes such as love, freedom, and revolution. He was against all bigotry, including religious and gender. Throughout his career, Nazrul wrote short stories, novels, and essays but is best known for his poems. He started new forms such as Bengali ghazals. Nazrul wrote and composed music for his nearly 4,000 songs. The are collectively known as Complete Works of Kazi Nazrul Islam, which are widely popular today. At the age of 43 (in 1942) he began suffering from an unknown disease. He was losing his voice and memory. It is often said, the reason was slow poisoning by British Government. He lived alone for many years. Invited by the Government of Bangladesh, Nazrul and his family moved to Dhaka in 1972. He died four years later.