Who was the black death spread throughout europe

  Once the black death begun in Asia in the 1200's , the Mongolian soldiers took it with them when their armies attacked the west in 1330.  The black death hit Constantinople, Istanbul, and in Turkey.  This was the worlds major trading center with merchants leaving they carried the black death with them.  It spread rapidly in the cramped and dirty conditions of mid-evil Europe.  It was a ship with some french soldiers are said to have brought the infection in July of 1348.  

to extend a country’s power and influence

this is a good question! i'll do some research and come back when i have the answer!