His Territory and capital
Imam Mahdi (p.b.u.h.) will surely rule over the entire world. He is the promised savior for whom all people have waited many centuries. When he reappears the goodness and justice will be spread all over the world. This is a fact to which many Hadiths have referred.
1. Many Hadiths say “Imam Mahdi (p.b.u.h.) will make the earth full of justice, when it is full of cruelty and injustice.” The word “earth” refers to the entire world or the whole planet. There is no reason to conclude that earth refers to one part of the world.
2. Some Hadiths narrate names of some regions or countries which are far and widespread all over the world. For example, “Rome” of that time, which is named in some Hadiths, included Europe and it can be concluded that America is also a part of “Rome” “China” refers to all countries of Eastern Asia as, Japan, Korea, Malaysia, Indonesia, etc. and “India” includes Pakistan, Afghanistan, etc. “Constantinople” or Istanbul, in Turkey, was the gate of Europe and it was a strong Castle. This importance makes conquering it a splendid victory.
Surely, these were some examples and because of the level of knowledge at that time some names have been mentioned in Hadiths. Some other regions are: Deylam, Turkey, send, Caspian, etc. this expansion and important regions show that he will take control of the entire world.
3. Some other Hadiths clearly mention his global rule over the world. The holy prophet (p.b.u.h.) says:
“Almighty God has informed me: “I shall make My religion overcome all other religions by them [= twelve Imams] and shall rule over the entire world by them and shall clear the world of my foes when the last of them [Imam Mahdi (p.b.u.h.)] rises up. So I shall make him the ruler of east and west in the world.”
Imam Baqer (p.b.u.h.) says:
“Our Upholder shall rule over the east and west and God shall make his religion overcome all other religions and no matter how it may disgust pagans…”
His capital is Kufa. It will be a big city which will include Najaf as well. That is why in some Hadiths Najaf is introduced as his Capital. Imam Sadeq (p.b.u.h.) says:
“The center of his reign is Kufa and he makes judgments in the [great] Mosque of Kufa.”
The interesting point is that Kufa was the center of Imam Ali (p.b.u.h.)’s reign and its famous Mosque is one of four famous mosques for Muslims. Imam Ali (p.b.u.h.) prayed there and made his speeches there and finally he get killed there.

The Length of his Reign
The world waits for the rule of justice to finish the long rule of cruelty and injustice.
The last proof of God who is the promised savior of the entire world will come back and rule over the world. Then the kingdom of God will be established on earth and will last forever!
This kingdom begins with Imam Mahdi (p.b.u.h.) and will last until the end of days and Judgment day.
In the previous Hadith of the holy prophet (p.b.u.h.), he says:
“[God informed me that]… then I will make his reign firm and the rule over the world will last forever by My favorite Servants until the Judgment day.”
His reign is certainly the kingdom of God on the earth and it will be followed by the rule of goodness over the world. It will be a new beginning to the life of mankind. Then the entire world will be under the rule of Allah.
Imam Baqer (p.b.u.h.) says:
“Our Reign is the last one and there shall remain no one claiming to rule over people but they will rule before us. So, when our turn comes and they see our method, they cannot claim they could rule the same as us.”
Therefore, the length of divine rule over the world is different from the rule of Imam Mahdi (p.b.u.h.) himself. He will rule the rest of his life, according to Hadiths, and will pass away at last.
His reign should be as long as he could manage to establish his government of justice all over the world. But we cannot guess how it can take to clear the world from injustice and cruelty from the world, and we should refer to Hadiths for this. Considering his unique abilities and his divine capabilities and also God’s miracles to help him, we can guess he can manage all these in a short time.
We should add his excellent supporters and universal preparedness to accept God’s rule to all above factors. Then we can conclude that the rule of justice, which all mankind was unable to establish for centuries, can be established in a short time, as for example less than ten years, by Imam Mahdi (p.b.u.h.)
There are lots of various Hadiths about the length of his reign. Some indicate he will rule for five years; others say his reign will be 7, 8, 9, or 10 years. There are some Hadiths saying he will rule for 19 years and a few months, some say forty years and others say three hundred and nine years.
It is not clear why these Hadiths are very different and it is surely difficult to choose one as the most authentic one. But some Shiite scholars accept 7 years of rule.
Some others say he will rule for seven years but each year is equal to ten years.
Imam Sadeq (p.b.u.h.) says:
“Imam Mahdi (p.b.u.h.) rules for seven years which are equal to seventy years of your time.”
Majlisi says:
“Reviewing Hadiths about the length of Imam Mahdi (p.b.u.h.)’s reign, we should consider these possibilities: some Hadiths refer to the entire length of his reign and some others refer to the time it will be firm and stable.
Some Hadiths refer to the years the same as our time and some others refer to the years of Imam Mahdi (p.b.u.h.)’s time which are longer. And God knows the truth.”

His Method:
Every ruler is known by his method of management. Imam Mahdi (p.b.u.h.) will follow a specific method of managing and ruling in his global reign. Here let us review some Hadiths about his method of ruling over the world.
The significant paint is that according to Hadiths his method is the same as the holy prophet (p.b.u.h.)’s method.
As the holy prophet (p.b.u.h.) fought against barbarism and ignorance, Imam Mahdi (p.b.u.h.) will fight with modern barbarism, which is worse than the old one; as the holy prophet (p.b.u.h.) established a new society based on virtues and spirituality, he will renew the world and refresh the atmosphere with the essence of morality and spirituality.
Imam Sadeq (p.b.u.h.) says:
“Imam Mahdi (p.b.u.h.) will do as the holy prophet (p.b.u.h.) did. As the holy prophet (p.b.u.h.) destroyed the wrong traditions of barbarism, Imam Mahdi (p.b.u.h.) will destroy the heresies and wrong beliefs and will renew Islam.”
This is his general policy which Imam Mahdi (p.b.u.h.) will take, but different situations cause different conditions and he may change some methods his management.

a. His Method of fights
Imam Mahdi (p.b.u.h.) will destroy all castles of paganism and atheism and will invite every one to join Islam.
The holy prophet (p.b.u.h.) says:
“His method is like mine and he makes people follow my way.”
However, Imam Mahdi (p.b.u.h.) will come back when the Truth is clearly introduced to people.
According to some Hadiths, Imam Mahdi (p.b.u.h.) will find the real versions of the Holy Bible and Torah in a cave in Turkey. Then many Jews and Christians covert to Islam and believe him.
He holds many signs of previous prophets as ring of Solomon stick of Moses and armor and flag of Mohammad. These signs make many people believe in him. He is also supported by divine help and tries to fulfill goals of prophets and make justice widespread. In such a bright environment, in which the truth is completely distinguished, just the real followers of Satan, who has totally forgotten their nature. They are the ones who just seek evil and Imam Mahdi (p.b.u.h.) will kill them all and will destroy their army. This is the method which the holy prophet and Imam Ali (p.b.u.h.) also took.

b. His Judgment
Imam Mahdi (p.b.u.h.) will institutionalize justice with his powerful system of judiciary. That will be exactly as the system which Imam Ali (p.b.u.h.) used. He tries to restore the rights of people and will punish any kind of cruelty wherever he finds it. His treats people so fairly that every one wishes those who are dead, were alive then and could be treated justly.
According to some Hadiths his judgment is like Solomon and David (p.b.u.t) and with his divine knowledge, he makes his decisions not with the help of evidences.
Imam Sadeq (p.b.u.h.) says:
“when our Upholder rises up, he judges like Solomon and David (p.b.u.t), without the help of any without or evidence.”
This may be because of his divine knowledge. In other words, since divine support lets him make just decisions, the real justice will be fulfilled ; but when we use witnesses, who are surely human beings, there may be some mistakes in the judgment. Any way, it is difficult now to understand how he makes his decisions on judicial cases, but it is surely compatible with the situation of those days.

c. His Management
Capable agents who do their best to help the country develop, improve the government. In this way, they reach their goals much easier. Imam Mahdi (p.b.u.h.), the leader of the entire world, chooses the best of his apostles as the ruler for different parts of the world.
They all have characteristics of good managers. They are dedicated managers, brave rulers and devoted leaders. They take decisive actions. However, Imam Mahdi (p.b.u.h.) controls all of them carefully and precisely. He never forgives misconducts. This characteristic is a noticeable sign of Imam Mahdi (p.b.u.h.) which makes him distinguishable from other rulers, for in our world conservative rulers have forgotten this important factor.
The holy prophet (p.b.u.h.) says:
“Mahdi (p.b.u.h.) can be distinguished by these characteristics: He is strict with his agents, generous with people and beneficent with the poor.”

d. His Method in Economy
He treats everyone equally. This is the method of the holy prophet (p.b.u.h.) which has been forgotten after him. Therefore, instead of equal distribution of wealth, some people got richer day by day and some others, got poorer. This has caused a deep gap between social classes. The only rulers after the holy prophet (p.b.u.h.) who treated others justly were Imam Ali and Imam Hassan (p.b.u.h.). In their short time of reign, they distributed the treasury of Muslims equally in the society. But after them, Umayyad possessed the treasury of Muslims and used it for their own purposes; they gave public lands and properties to their kin and little by little it became a formal tradition which let the rulers to use the treasury of Muslims personally. But Imam Mahdi (p.b.u.h.), who is the symbol of justice, distributes all the wealth of people among them equally. He never alleges discrimination against any one and never gives fields or properties to some people.
The holy prophet (p.b.u.h.) says:
“Our Upholder vanishes the given properties which previous rulers donated to their kin or possessed them, so that there will remain no given land or property.”
The other method he follows is in welfare. He prepares the welfare for all people and gives them lots of money. In this way whoever asks him money, he gives him a lot.
The holy prophet (p.b.u.h.) says:
“…He grants [money] a lot…”
when people live easily and have no concern about money or financial problems, they can worship God in tranquility. This is the goal that Imam Mahdi (p.b.u.h.) pursues.

e. His personality.
For Imam Mahdi (p.b.u.h.) ruling over people is helping and supporting them; helping them to reach perfection and supporting them to fulfill divine duties. He does not seek power in order to exploit the weak and poor, but to help them. He is exactly the same as the holy prophet and Imam Ali (p.b.u.t.). He holds all treasuries in the world and all existed properties. But he lives like the poorest members of the Society. Imam Ali (p.b.u.h.) describes him:
“Imam Mahdi (p.b.u.h.) swears that he walks like his people and dresses like them and rides a steed like everyone else and contents with little things.”
Imam Ali (p.b.u.h.) was himself exactly like this, and Imam Mahdi (p.b.u.h.) will follow his fathers.
Imam Sadeq (p.b.u.h.) says:
“when our Upholder rises up, he shall dress Imam Ali (p.b.u.h.)’s gown and shall follow his Method.”
He is strict about his life, kind to his people and the only thing he wants about people is happy and easy life.
Imam Reza (p.b.u.h.) describes him:
“Imam is the best friend, the kind father, the full brother, the devoted mother and the safe haven or people in dreadful disasters.”
Surely he is so intimate with his people that everyone seeks safety in his haven. The holy prophet (p.b.u.h.) says:
“His people turn to him like bees turning to the queen bee.”
He is the symbol of leadership: a leader who lives among people and knows their difficulties and solutions to all those problems.
He does his best to cure them and does this just in cause of Allah. We will surely feel safe and happy with such a leader.

Public Satisfaction
Public satisfaction is one of important goals of all governments. But they mostly fail to get it, for they fail to fulfill most of people’s needs. On the contrary, Imam Mahdi (p.b.u.h.) is accepted and admired by all people and his global justice satisfies everyone. The holy prophet (p.b.u.h.) says:
“Hereby I announce the good news of Mahdi (p.b.u.h.)’s coming… All the habitants of earth and heaven are satisfied with him (and his reign). How can anyone be unsatisfied when all the people find out that their salvation and good ending in material and spiritual affairs is due to his divine reign.”
As the last word let us narrate this Hadith of Imam Ali (p.b.u.h.).
“God shall confirm him [= Imam Mahdi (p.b.u.h.)] with His angels, and shall save his followers, and shall support him with his signs, and shall make him conquer all the world, so all people join him willingly or discontentedly. He makes the world full of justice, light and proofs. All people believe him until the time there remains no pagan.
All evil turns to goodness and beast reconcile with each other. The earth is full of prosperity it rains a lot. The treasures inside the earth appear to him. How lucky are those who see him and listen to him.”