The "Rightly Guided Caliphs" refers to the first four leaders of the Islamic community after the death of the Prophet Muhammad. These caliphs—Abu Bakr, Umar, Uthman, and Ali—are known for their close companionship with Muhammad and their commitment to his teachings. They played a crucial role in expanding the Islamic state and establishing its governance. Each caliph contributed to the development of the early Muslim community. Abu Bakr focused on unifying the tribes of Arabia, while Umar expanded the empire into Syria and Egypt. Uthman is known for compiling the Quran, and Ali is recognized for his leadership during a time of internal conflict.