In that year the disappearance of MY SON [HAZRAT MAHDI (AS)], WHO WILL HAVE THE RED FLAG AND AFTERWARDS GREEN FLAGS, will be announced.
(Sheikh Muhammad bin Ibrahim Nomani, al-Ghaybah al-Nomani, p. 170)
According to this hadith of our Prophet’s (saas), Hazrat Mahdi (as) will first appear from Turkey with the Turkish flag and will then become the spiritual ruler of other Islamic countries with their green flags. He will be instrumental in the founding of the Turkish-Islamic Union and will assume the spiritual leadership of it.