All of these were empires of South America except for the Sumerian Empire. The Mayans lived in modern-day Mexico and Guatemala from about 300 C.E. to 900 C.E. The Mayans are most well known for their extraordinary astronomical observations and understanding. The Incan Empire included most of modern Peru, Ecuador, and Bolivia as its territory, lasting for a few hundred years, between roughly 1300 and 1550 C.E. The Aztec Empire existed in central Mexico around the same time as the Incas. They were completely destroyed by the arrival of the Spanish conquistadors and Hernan Cortes. The Olmec Empire existed in a much earlier time period than the rest of the South American civilizations previously discussed—from about 1500 B.C.E. to about 400 B.C.E—and ruled in a similar area of Central America to the Mayans. The Sumerian Empire on the other hand is one of the earliest known civilizations from the ancient Mesopotamia region of the world (what is now Iraq and Syria). The Sumerian Empire existed several thousand years ago and is considered important to historians because the earliest known writing that has been found is in the language of the Sumerian Empire.

Confucianism is a philosophy that arose in China 2500 years ago. It is also sometimes called a religion. Confucianism’s primary tenets are a deep respect for ancestors and an obedience to legal tradition and order.

The House of Plantagenet is an important ruling family in English history. They ruled over England from the mid-twelfth century until about the mid-fifteenth century. Notable Plantagenet monarchs include King Henry II, Richard the Lionheart, and King John (the man who was King when the Magna Carta was signed). They were also in power when the Hundred Years’ War was waged against France.

The Holy Roman Empire was nominally created from the ruins of the Western Roman Empire during the so-called Dark Ages of European history. Charlemagne, a Frankish King in the early ninth century, was crowned Holy Roman Emperor in 800 C.E.

The Protestant Reformation began in Europe in the early sixteenth century. Specifically it can be traced to 1517, when the German monk nailed his 95 Theses to the door of a Church in Germany. Lutheranism was the first major religion of the Protestant Reformation, followed shortly by Calvinism (John Calvin), Zwinglism (Ulrich Zwingli), and Anglicanism (Henry VIII).

An armistice is a temporary halt in conflict during a war; it is often followed by the signing of a peace treaty, but when two sides cannot reach agreement it may simply be a temporary break before the fighting resumes. The policy of allowing an enemy or a rival to achieve certain gains in the hope that they will then be appeased is called "appeasement." A smaller state or nation that is dependent on a larger state for protection is called a "satellite state." A vote by the people to directly decide the outcome of an issue is called either a "plebiscite" or a "referendum."

The Kellogg-Briand Pact was signed in 1928 by most of the powerful nations of the world at the time. Signed between World War One and World War Two, it was meant to prevent a future outbreak of world war. Considering that World War Two broke out a decade later, and that Japan invaded Manchuria in 1931, it can hardly be seen as a success, yet it was an important step in the history of civilization, because it was the first major attempt to renounce warfare as a means of foreign policy.

The term, "Apartheid," refers to a period in South African history when the government actively promoted and sponsored discrimination and segregation on the basis of race. It ended in 1990.

The Hundred Years’ War was a series of conflicts waged between England and France from 1337 to 1453. The war was primarily fought for control of the Kingdom of France and ended with English finances exhausted, with civil war brewing as the majority of France remained outside of English control.

The Crusades is the name given to a series of military campaigns waged by the nations of Western Europe between 1095 and 1487 C.E. The primary goal was to retake Jerusalem and the Holy Land for Christianity from the Islamic Empires that held sway there at the time, but some crusades were declared against heretic Christians in Europe.