Diophantus Puzzle

Diophantus was a Greek mathematician whose work laid down important foundation for the development of algebra. Listed on Wikipedia is an interesting puzzle to guess the age of Diophantus:

'Here lies Diophantus,' the wonder behold.

Through art algebraic, the stone tells how old:

'God gave him his boyhood one-sixth of his life,

One twelfth more as youth while whiskers grew rife;

And then yet one-seventh ere marriage begun;

In five years there came a bouncing new son.

Alas, the dear child of master and sage

After attaining half the measure of his father's life chill fate took him. 

After consoling his fate by the science of numbers for four years, he ended his life.'

This Diophantus puzzle has a similar flavor to the Carroll's puzzle in my previous post. Here, however, a finite sequence of moves (in fact, events in the timeline) is applied to an unknown - Diophantus's age. 
How long did Diophantus live?