Many scholars agreed that the first major signs will be the Mahdi.
Who is the awaited Mahdi?
Literally in Arabic, Mahdi means the chosen awaited one. His name is Muhammad. You’ll find this authentic hadith that Prophet Muhammad (peace be upon him) said that:
“… His name is like my name and his father’s name is like my father’s name.”
He resembles Prophet Muhammad (peace be upon him) not in his physical form but in his character.
Allah said about the Prophet Muhammad’s character:
You are on an amazing character. (Quran 68:4)
The Just Ruler
So the Mahdi will resemble the perfect character of Prophet Muhammad (peace be upon him). He will rule and lead the Muslims until he transforms the world; he will fill it with justice and peace as it was filled with injustice and tyranny.
How many years did it take for the world to be in this terror and tyranny now, Al Mahdi, in a short span of time, will change this state of the whole world from injustice to justice, from tyranny to peace just as it was filled the other way. The balance will be returned with the coming of the Mahdi.
Some scholars say that the Mahdi’s born now, and some others say not yet. But the minor signs make it a possibility that he probably is right now here. Allah knows best.
The thing about the signs of the Last Hour is that we can never pinpoint them or give it a time span; we can only speak in general.
We find in an authentic hadith that Al Mahdi will appear in Makkah and the scholars will identify him with the descriptions that Prophet Muhammad (peace be upon him) placed about him: wide forehead, big sharp eyes, a thin nose which is slightly hooked on the top. (Muslim)