Best of the worshippers
Imam Ali ibn. Husain (AS), popularly known as Zaynul Abidin (the best of the worshippers) and Sayyid us Sajedeen (chief of the prostrators before God) , was the sole surviving son of Imam Husain, following the massacre of Prophet's family at the Battle of Karbala. He was the grandson of Imam Ali and Lady Fatima (Peace be upon them) , and great grandson of Prophet Muhammad (PBUH).
He lived in difficult times, having witnessed the martyrdom of most of his family and imprisonment of womenfolk, because they refused to bow to the authority of a despotic ruler. And yet, he produced such magnificent works as Sahifa-e-Kamela (a collection of prayers and supplications to Allah) and Treatise on Rights, which preceded Magna Carta by several centuries. These seminal works of Islamic Sprituality capture the essence of Islamic faith as religion of Peace.