An ancient language, but like Marathi, started its literary career pretty late. The script is Gurmukhi based on Devanagri. Punjab is divided into two distinct language areas: Hindi in West Punjab and Punjabi in East Punjab. This Eastern Punjab dialect developed into a literary language around the beginning of the 17th century whereas Hindki still remains a group of dialects. During medieval times, Punjab repeatedly bore the brunt of Afghan invaders and internal battles, and these warring times were not exactly feasible for any sort of literary or cultural expansion. Punjabi literature as such came into existence only from the end of the 16th century when Punjabi was already in its Middle Period. Gurmukhi script, created from the Nagari script, is claimed by Sikhs as the only proper script for Punjabi. Punjabi was evolving and Guru Nanak, the founder of the Sikh religion, gave a new lease of life to the language although it was still not in its pure form.