A Politics appeared in the ancient times. As soon is the first state, politics is emerged. The oldest form of government is a monarchy. In the ancient world, the head of state was usually a tsar. The tsar and his subordinates had to meet all the needs of the citizens, why the policy was considered an important and complicated science. But the tsar the rules does not everywhere, because in ancient China, the emperor rules. Even in the different tribes had their own heads: the leaders (вожди).
In the Middle Ages in Western Europe, appeared the state where the kings started to rule. Arabic caliphateIn the Middle East ruled by caliphs (халифы). There are the princes (князья) ruled in Ancient Rus (в Древней Руси). But in the Golden Horde (в Золотой Орде) khans ruled. In Iran, the shah of rules, but the sultan rules of Turkey in the Middle Ages.
In 1789, when the United States became independent, they became a republic. So there appeared the first republic.
There are two main forms of government now. It is a monarchy and a republic. A monarchy is absolute, dualistic and parliamentary. The absolute monarchy are Saudi Arabia (Саудовская Аравия), Vatican, Bruney, Qatar, Oman, Swaziland and the United Arabic Emirates. The dualistic monarchy are Morocco, Jordan (Иордания), Liechtenstein, Luxembourg, Kuwait, Monaco. The United Arabic Emirates are combination of absolute and dualistic monarchy. The parlamentiary monarchy are European monarchies, except Luxembourg, Monaco, Liechtenstein and Vatican. Japan, Lesoto, Butan, Nepal, Malaysia, Thailand and Tonga are parliamentary monarchies, too.
The republics are are presidential, parliamentary and mixed. The mixed republics are France Portugal, Finland, Poland, Lithuania, Romania, Slovakia, Slovenia, Serbia, Croatia, Montenegro, Russia, Ukraine, Armenia and Kyrgyzstan. The presidential republics are USA, many countries of Latin America and Africa. The parliamentary republics are Italy, Turkey, Germany, Greece, Israel, Suitzerland, Austria, India, Libya, Somalia and many countries, too.