The Basseri (باسری or باصری) are a Persian nomadic and pastoral tribe of the Fars Province in Iran. Their migratory area is around Shiraz. They are one of the five tribes of the larger Khamseh confederation. The "tent" is the basic unit of social organization among the Basseri. All tents have a recognized head that deals with the formal officers of the tribe, villagers, and other strangers. The Basseri economy stems mainly from sheep and goats. Basseries are mostly Persians. Their origin is the "Pasargadean" tribe. The Pasargadean tribe was the biggest tribe of Persia and the tribe who helped Cyrus The Great constitute the Achaemenid Empire. They were named "Karian" tribe in Sasanian Empire period. They were the rulers of some parts of south Persia and the Karyan city of Persia because they helped Ardashir I constitute the Sasanian empire. After the Muslim conquest of Persia they were under rule of Arabic Tribes of South Persia, who migrated to Persia after its conquest, till the constitution of the Zand Dynasty by Karim Khan. In Pahlavi Dynasty period they were settled by the government in 1930 and again started to decamp in 1941. After the Land Reformations of Iran, they were settled in the cities and the villages of Fars Province; but after some years, they again started decamping. After the Islamic Revolution of Iran because of the problems of being nomad including inaccessibility to modern facilities (hospitals, schools, etc.), successive droughts, destruction of the migration paths they again went to the cities and the villages of the province for living. The word "Basseri" was originally "Wastaryoshan", the commoners of Sasanian Empire period. A compound of "Wastary" and the "osh" suffix, the "W" phoneme in ”Wastary” was changed to "B" and the "T" phoneme was removed as it was easier to pronounce, therefore the word shifted to “Basseri”. Basseries are Shia Muslims, They became Sunni Muslims after the Arabs invaded Iran in the 7th century CE. They were force converted to Shi'ism following the Safavid invasion in the 16th century CE.