The answer to the missing blank above would be 'the Mongols'. The Mongols invaded Russia around 1300s, which arose to economic downfall and overall negative effect to Russia. Because of this, the Russian princes convened and fought to drive Mongols out of the country.
Answer:
Culture-Specific Theme:
bittersweet relationship between siblings
loss of American Indian culture in European colonies
Universal Theme:
Impacts of 9/11 on New Yorkers
Overcoming challenges
