Localized regions of the world where political, economic and cultural influence are dominant for a time. Hence depends on a particular era in a particular sphere of influence

Answer and Explanation:

I'm not sure of what is being asked here but I'll explain based on clues given: "particular era" and "sphere of influence".

Sphere of influence has to do with a state's influence or level of control over territories outside it's borders. It is mostly used with imperialism which is claim of rights and privileges over a large or great number of foreign territories for purposes of trade, military or investment purposes.

In history, a good number of imperialist governments in their different eras have risen and fallen with the most recent being modern colonialism, the Age of Discovery/Age of European Colonisation,started about 4 centuries ago by Portugal in their conquest of Morocco.

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.