Found: Boy sent by father to walk to Istanbul over 3 years

I'm looking for a book described by my dad, as a father sending his son (who is a bit of a "layabout" - (sorry) my dad's description) to walk to Istanbul over 3 years. The father gives him minimal money per week (or maybe per month) during the son's journey.

Maybe not an important detail, but ... starting from where? Fiction or non-fiction? How long ago did your dad read it?

How about A Time of Gifts by Patrick Fermor? (non-fiction, published 1977)

It takes three books (years?) to make it all the way: https://www.librarything.com/nseries/11205/On-Foot-to-Constantinople

I think the son started from London. I'll double check.

Yes! This is the book / series. Thank you very much. My Dad is very grateful and happy.

Found