For William and Kate, this traditional name would actually be an unusual choice. Though it was the most popular British male name for the first half of the 20th century, it had dropped to a lowly 100th place by 2011. An unlike most other names on this list, there’s not much Royal precedent. While John is a common name for popes, saints and various European monarchs, its roots among the British aristocracy is thin at best. The only King John of England was John Lackland, who reigned from 1199-1216 — the Magna Carta was signed during his rule in 1215. On the plus side, the name does carry some weight on Prince William’s mother’s side. Princess Diana reportedly considered naming her firstborn John, after her father, John Spencer, but was ultimately discouraged. The Duke and Duchess of Cambridge may decide to break with tradition on their child’s name; British bookies are laying 10 to 1 odds that they will.