Religious architecture often included high spires and steeples. Renaissance architecture reflected more influence from Greek and Roman influences. In 3-4 sentences, discuss the potential reasons for these architectural types. Why were
these buildings important? How did they represent European culture?

Since the conversion of Constantine to Christianity and his declaration of Christianity as the official religion of his Roman State, the steeples, the pointed roofs of churches, have been included in church buildings . He via his  "Edict of Milan" in 313CE, made the Roman Empire a religiously neutral state. This led to the merging of Pagan and Christian symbols.

Church steeples can be traced back thousands of years to Egypt and pagan worship Steeples on the churches, and obelisks (such as the one at the Vatican and our Washington Monument), which depict the  influence of our  ancestors who worshipped phallus.

The symbol for Priapus - a Greek god of fertility was an exaggerated phallus. The male phallus was also very important to the cult of Osiris in the ancient Egyptian religion. The obelisk is a phallic symbol used in worship of the sun god Ra (Egypt).  Over the years, the tall poles became a part of the architectural design of our earliest churches.

The obelisk was a strong influence on the the Ancient Romans. Currently, Rome now has more than twice the number of  obelisks standing in Egypt. It also very clear to see the connection between the obelisk and the common church steeple, which many historians have pointed out.

It's interesting to note that every major power centre in the world such as Rome, London, and Washington DC, has an obelisk.  

Cheers!