Zain-ul-Abidin, also known as Ali ibn Husayn, was the fourth Imam in Shia Islam and the son of Husayn ibn Ali, the grandson of the Prophet Muhammad. He was born in 658 CE and is revered for his piety, knowledge, and leadership during a tumultuous period in Islamic history, particularly after the tragic events of Karbala. Zain-ul-Abidin is best known for his collection of supplications and prayers, compiled in a book called Sahifa Sajjadiyya. This work emphasizes spiritual growth, ethical conduct, and social justice, making it a significant text in both Shia and Sunni traditions. His life exemplified resilience and devotion to faith despite facing immense challenges.