The English Wikipedia passed the 2 million-article mark on September 9 , 2007 , making it the largest encyclopedia ever assembled , eclipsing even the Yongle Encyclopedia ( 1407 ) , which had held the record for exactly 600 years . English Wikipedia passed the two million-article mark on September 9 , 2007 , making it the largest encyclopedia ever assembled , eclipsing even the Yongle Encyclopedia ( 1407 ) , which had held the record for exactly 600 years .