What social, political and military developments contributed to the rise of european nations in the medieval period

The militaries of nations started growing in power and since there was also a rise in economic power as well as cultural developments, this resulted in stronger and more unified nations. Politically, groups of states started uniting into big states while socially people started gathering slowly around the idea of nationalism, which flourished even more in the time to come, in the 18th century. 

It turns into vapor and goes into the atmosphere