John Ibn Howey Al-Kalabi is an Abyssinian slave who was at the service and companion of Abu Thar Al Ghefari, Imam Ali (AS), Imam Hassan (AS) and subsequently Imam Hussain (AS). John was taught the the holy Qu’ran and the traditions of prophet Mohammed (pbuh) by Imam Ali. He was freed by Imam Hussain (AS) but John chose to remain, saying ‘Oh Imam I wish for my blood to be sacrificed for your sake and the sake of Islam’ and asked to be accepted as a companion of Imam Hussain (AS).
A day before Ashura, John was responsible for preparing the swords. During battle he killed 25 of the army of Omar Ibn Sa’ad and then attained martyrdom.