Abraham -
A Mesopotamian man thought to have lived around 1800 BCE. Abraham features prominently in the Hebrew Bible and the Qur'an and is an important figure in Judaism, Christianity, and Islam.
Abraham is believed to be the patriarch of the three major monotheistic religions. Abraham was one of the first people to teach the idea that there is only one God.

Moses -
Moses was a Jewish prophet and leader descended from Isaac who lived during the 14th century BC. According to tradition, he led the Israelites out of slavery in Egypt in what is known as the Exodus.
He is the most important figure in Judaism, believed to have written the Torah (the first five books of the Hebrew Bible). Moses is an important prophet in both Christianity and Islam.

Jesus -
Jesus was a Jewish man and teacher believed by Christians to be the Son of God and the Messiah. He lived in the Roman province of Judaea (now part of modern-day Israel) during the first century CE.
He is the most important figure in Christianity, held by tradition to have been the Son of God. Christians believe that Jesus allowed himself to be crucified by the Romans to atone for the sins of humanity.

Muhammad -
Muhammad was an Arab merchant who lived during the sixth and seventh centuries CE. He spent most of his life in the city of Mecca on the Arabian peninsula (modern-day Saudi Arabia), before migrating with his followers to Medina.
Muhammad is the founder of Islam. Muslims consider him to be the last in a line of prophets of God. His prophecies, collected in the Qur'an, are believed by Muslims to be the word of God.

Five Pillars of Islam -
The Five Pillars of Islam are a set of acts considered by Muslims to be central to their faith. They are shahadah (statement of belief), salat (daily prayers), sawm (fasting) during Ramadan, zakat (alms-giving), and hajj(pilgrimage to Mecca).
Muslims believe that observation of the Five Pillars is a sign of commitment to Islam.

Merovingian -
The Merovingians were a line of Frankish kings beginning with Clovis I. The Merovingians were a group of Germanic Franks that established a kingdom in the old Roman province of Gaul in the wake of the collapse of the Western Empire. The Frankish line began in 481 CE, though it had its roots in earlier tribal leaders. Clovis I, who converted to Christianity, was a brutal man who expanded his territory at the expense of other kingdoms and even his own relatives.
The Merovingians ruled Gaul (present-day France) for approximately 200 years. But the expansion of the kingdom and Clovis's acceptance of Christianity helped to spread the influence of Christianity across Europe.

Charlemagne -
Charlemagne was a Frankish king who united the Franks and conquered neighboring lands in the old Roman province of Gaul. Born in 742 CE, Charlemagne was a pious Christian who sought to reform the church and improve education in his kingdom.
Charlemagne laid the groundwork for political and economic patterns that would dominate the rest of the medieval period in Europe; conquests formed the basis of what would be the Holy Roman Empire.

Holy Roman Empire -
The Holy Roman Empire was an empire composed of lands in Central Europe, largely comprising what is now Germany. Its origins go back to the empire of Charlemagne, but the actual Holy Roman Empire didn't begin until 962 with Otto I.
The empire was a major political power in Europe for a long time and continued to exist for over 800 years. The empire, and its relationship with the Church in Rome, helped to spread the influence of Christianity throughout northern Europe.

Crusades -
The Crusades were a series of military expeditions between the 11th and 13th centuries on behalf of the Roman Catholic and Orthodox Churches to establish control over the Holy Land. Christians had been making pilgrimages to the Holy Land for years. But these pilgrimages stopped as a product of the prohibitive tactics of the Seljuk Turks. When the Byzantine emperor was looking for a way to check the Turkish advance, he used the general Christian passions about the Holy Land to launch holy wars against Turks.
While the Crusades ultimately failed to maintain control of the Holy Land, they did succeed in expanding the medieval European world, bringing Muslim knowledge to medieval Europe, and increasing the wealth and power of the Catholic Church.

Pope Urban II -
Pope Urban II was a Roman Catholic pope between the years 1088-1099. He is most famous for responding to the Byzantine emperor's plea for help and defending the empire against the Turks by vigorously calling for Christians to begin a holy war.
Pope Urban II called the Council of Clermont and issued a call for the First Crusade.

Richard the Lionheart -
English king Richard I was known as "the Lionheart" for his bravery and leadership in battle. He is most famous for participating in and leading the Third Crusade. He battled with and won many victories against the Muslim military leader Saladin; however, he was never able to win back Jerusalem.
While his leadership in the Third Crusade is his most famous achievement, he is also prominent in some English folklore. According to the legend, it is King Richard's absence that brought about the circumstances that resulted in Robin Hood.

Saladin -
Saladin was a Kurdish Muslim warrior who gained prominence fighting in the Holy Land against the Crusaders. In 1187, he successfully conducted a coordinated force that retook Jerusalem in 1187.
Saladin is most important for his role in uniting the Muslims of Egypt, Syria, and surrounding lands and driving the Christian Crusaders out of Jerusalem. Before Saladin, the major weakness of the Muslim defenders was their disunity.