A India India has the highest population and population density
the correct option to this question are
the catholic church unified different kingdoms of Europe under the umbrella of the church. An example is when the church crowned kings as emperors of the holy catholic empire.
the catholic church intervened and settled disputes between rival kings and lords. whenever, there were disputes the king was always at the forefront to handle and resolve disputes.
The answer is : The crusades.
The Crusades were a series of religious wars between Christians and Muslims started primarily to secure control of holy sites considered sacred by both groups. In all, eight major Crusade expeditions — varying in size, strength and degree of success — occurred between 1096 and 1291.