Everybody on this planet has what is known as a MRCA – or Most Recent Common Ancestor. There are different estimate for when this person lived, but one study believes that it may be as recently as 0 AD. So your family tree could start with this person, and by the time it got down to you, would include everybody in the world. Also, if you went further up the tree from your MCRA, you would eventually find your early African Homosapien ancestors
Also, if you are European, your MRCA may have lived around 600 years ago, so if you go back far enough, your family tree would include the Queen.