The
Who's Who in Medieval History resource has pages offering salient information for interesting and significant figures of the Middle Ages -- and it's still growing. Most, if not all, of the truly important individuals are included. But important isn't necessarily "popular." Here is a countdown of the medieval people whose Who's Who pages drew the most visitors in 2011.

Public DomainHe was known as "Leif the Lucky," and he made a historic voyage to north America almost 500 years before
Columbus.

Public DomainWith his Norman army, William invaded England in 1066, distributed the conquered lands among his associates, and not only began a new dynasty, but began a new era in English history.
The closest friend and companion of the prophet Muhammad, Abu Bakr was one of the first converts to Islam and the first Muslim caliph.

Public DomainThe first Roman Emperor to profess Christianity, Constantine's sponsorship of the religion would change the face of western Europe and create a foundation for Christian prominence throughout the Middle Ages.

Public DomainThe father of Leif Ericsson (#10 on our list), Erik was exiled from Iceland for manslaughter and sailed west in search of new opportunities. What he found was Greenland.
Harold took the crown upon the death of
Edward the Confessor, and for several months reigned wisely. Then William the Conqueror (#9 on our list) invaded England, and he was killed by William's troops in the Battle of Hastings.

Public DomainA superb sculptor in marble and in bronze, Donatello even developed his own style of relief. His bronze sculpture of David is the first large-scale, free-standing nude statue of the Renaissance.

Public DomainEven from a distance of more than a thousand years, the King of the Franks and Lombards (and Emperor, though he rarely used the title) seems larger than life.

Public DomainKnown as "Lionheart" for his courage and prowess on the battlefield, Richard was one of the most popular kings in English history.

Public DomainRodrigo Díaz de Vivar, known as the "Cid" (from the Arabic
sidi, meaning "Sir" or "Lord") was a remarkable military leader and is the national hero of Spain. He is immortalized in legend and song, including the 12th-century epic
El cantar de mío Cid ("The Song of the Cid").
That's our top ten for 2011! I'm a little disappointed that no women made it (sorry, not even close); but About does have a marvelous Women's History Site, Guided by Jone Johnson Lewis, so I'm sure visitors are finding a wealth of information about medieval women (and historic women of other eras) there.
Of course, "most popular" doesn't necessarily mean "most important." Feel free to come to our forum and share who you think are the most important individuals of the Middle Ages. And don't forget to check out our Best of 2011: Most Popular Topics.
Update: the list for 2012 is now online. Check it out!