During whose caliphate did the significant conquest of Persia (the Sassanid Empire) largely take place?

Explanation

– The significant conquest of Persia, effectively ending the Sassanid Empire, largely took place during the caliphate of Umar (RA), reflecting the substantial territorial expansion achieved during this period.
– Key battles during this campaign included the Battle of Qadisiyyah and the Battle of Nahavand, which severely weakened Persian resistance to the advancing Muslim forces.
– For exams, remember that this conquest brought a significant Persian population and rich cultural heritage into the broader Islamic empire, influencing subsequent Islamic civilization.