What is a bullwark?

What is patriacry? How is Charlemagne a barbarian? What is a word explaining why something wrong has been done? Who would wear a medieval crown? What rights were townspeople given in medieval societies? In the Middle Ages what were villiens? Why were western nations able to control parts of China in the 1800s? What is the head of the roman religious observances called? When did people start building the transcontinental railroad? Who called for the crusades against the Muslims? When were condoms first used? Who founded The Principality of Kiev? Where does the surname Sawtelle originate from? What is the origin of the word colonialism? What did pax romana mean when the temple doors of janus were opened? Was the hoplitodrome a chariot race? Who is Mary Wollstrongcraft? What was slavery like in Europe? How might a strong organized empire defend its frontier? The First Triumvirate was unsuccessful because?