Did you know that Alexander, the fourth most popular baby boy name in the U.S., is also the longest baby name in the top 10? The shortest is #9, Noah.

And it's etymologically related to the #15, Andrew. Both names, which were originally Greek, include an element that stems from the Greek word for "man."

The full definition of Alexander is "defending men."

Other forms of the name include Alasdair (Scottish), Alejandro (Spanish), Alexsandr (Russian), Alessandro (Italian), Alexandre (French), Alexandros (Greek), Iskandar (Arabic) and Oleksandr (Ukranian). Nicknames include Al, Alec, Alex, Lex, Sandy, Xander and Xan.

Here's how the baby name Alexander has ranked in the U.S. since the year 2000:

2009 - 4th most popular baby boy name
2008 - 6th
2007 - 11th
2006 - 12th
2005 - 12th
2004 - 15th
2003 - 16th
2002 - 15th
2001 - 20th
2000 - 20th

It's quite popular, but that's nothing new--it's been popular for centuries. The name was first popularized by Alexander the Great over 2,000 years ago.

Here are some other notable people who have been named Alexander:

• Alexander Fleming (1881-1955) - Scottish biologist.
• Alexander Graham Bell (1847-1922) - Scottish-born inventor of the telephone
• Alexander Hamilton (1755-1804) - U.S. Founding Father
• Alexander Korda (1893-1956) - Hungarian-born film director
• Alexander MacKenzie (1764-1820) - Scottish-Canadian explorer
• Alexander McCall Smith (born 1948) - Scottish professor and writer
• Alexander McQueen (1969-2010) - British fashion designer
• Alexander O'Neal (b. 1953) - American singer
• Alexander Pope (1688-1744) - English poet
• Alexander Popov (b. 1971) - Russian swimmer
• Alexander Pushkin (1799-1837) - Russian writer
• Aleksandr Solzhenitsyn (1918-2008) - Russian writer
• Aleksandar Djordjevic (b. 1967) - Serbian basketball player
• Alexandre Dumas (1802-1870) - French writer
• Alec Baldwin (born 1958) - American actor

Alexander also happens to be a common surname. According to the 1990 U.S. Census, it was one of the top 100 surnames in the country. It's also common in England, Scotland and Wales.

10,000 Most Popular Baby Boy Names Want more than the top 100 or top 1,000 baby boy names? Here's a complete list of the 10,000 most popular baby boy names in the nation! Click to learn more.