Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

The Church of the Savior on Spilled Blood, built on the site of the assassination of Tsar Alexander II, is in which Russian city?
church of the savior on blood

Which English king was the son of Edward, the Black Prince?
edward, the black prince

Whose resignation prompted the Eastleigh by-election in February 2013?

eastleigh