A Lord would protect a king and provide wealth in return for land and protection. Knights and nobles would provide protection for serfs and other classes in exchange for labor and production.
This isn't the best thing because this is from google with some of my own words so try swapping words out and replacing some to not get in trouble for plagiarism. Wish you luck though!
Large volcanic eruptions can. heavily impact the surrounding areas. An example would be Pompeii where deadly gas and ash along with mudslides completely destroyed surrounding cities and polluted the air overhead for a very long time.
