The seventeenth of Safar is the martyrdom anniversary of Imam Ar-Reda (peace be upon him)..

On the seventeenth of the month of Safar, Imam Ali son of Musa son of Ja'far son of Mohammad son of Ali son of Al-Hussayn son of Ali son of Abi Taleb (Allah's prayers be upon them all) in the city of Tus.
He (peace be upon him) was born in Medina the 11th Dhu Al-Qi'dah 148 AH, in the same year in which his grandfather Imam As-Sadeq (peace be upon him) was martyred according to most of the historians. Other few historians said his birth was in the year 153 AH.
His nickname: Abu Al-Hassan
The inscription on his ring: "Hasbiya Allah", or "MashaAllah La hawla wala Quwwata Illa billah".
His titles: As-Saber [The patient], Az-Zaki, Al-Wafiy, Al-Fadel, Al-Siddiq, Siraj Allah, Qurrat 'ayn Al-Mu'mineen, Makeedat Al-Mulhideen..
"Ar-Reda" is his most famous title, the scholars say that he was given this title because he represented the satisfaction of the Almighty Allah and the satisfaction of His messenger and the Imams (Allah's prayers be upon them), and others say that he (peace be upon him) had this title because he was patient face to the tribulations and calamities he experienced.
His mother: Historians say she (peace be upon her) has many titles: "Umm Al-Baneen", "Najma", "Sakan", "Shaqra", "Tahira" and "Al-Khayzuran".
The duration of his Imamate after his father 20 years, and it was in the same time with the beginning of the end of the Abbasid Caliphate of Harun, He (peace be upon him) was martyred in Tus in Khorasan in Safar 203 AH and he (peace be upon him) was then 55 years old.