Kingdom vs Empire
The terms kingdom and empire are generally used in the same sense though there are some differences between the two. An empire is ruled by an emperor whereas a kingdom is ruled by a king.
In other words it can be said that a country with a king (or queen) as the head of the state is called a kingdom. The term empire is derived from the Latin ‘imperium’. Imperium means power or authority. States and people of various ethnic groups constitute an empire. Some of the best examples of empires of the world are the British Empire, the Spanish Empire and the Holy Roman Empire.
One of the most powerful western empires was the Roman Empire. It is interesting to note that prior to the Roman Empire, the kingdom of Macedonia became an empire too under Alexander the Great.
A kingdom is a domain ruled by a king or a queen. A kingdom ruled by one king is called a monarchy whereas a kingdom ruled by many kings is called oligarchy. If it is ruled by two kings it is called diarchy. An empire on the other hand comprises of a set or regions ruled separately by governors and viceroys or vassal kings that rule in the name of the emperor.
An empire contains many provinces and colonies as well. The British Empire is again the best example of an empire that contained provinces, colonies and small kingdoms too such as Kingdoms of England, Scotland and Wales.
The United Kingdom comprises the England, Scotland and Wales that fall under the direct rule of the monarch (king or queen) where as the British Empire comprised a collection of countries (known as commonwealth countries, previously British colonies) around the world that were once under British rule, but not part of the British Kingdom.
In India, the example of kingdoms are the Chera kingdom, the Chola kingdom and the Pandya kingdom down in the south of India. One of the well-known empires in India is the Mauryan Empire. The Mauryan Empire was a powerful empire in ancient India. It was ruled by the emperors of the Mauryan dynasty between 321 BC and 185 BC.