Darko Kerim Bey was the Head of Station T, Turkey and was one of the best men MI6 had anywhere according to M. He helped Bond in a mission to escape from Istanbul with Tatiana and a Lektor decoding machine, eventually getting killed by SPECTRE Operative Red Grant.
I hope you have just as much finding them as I did hiding them. If you find any of the caches along the way in need of attention, please contact me via my GC.com profile.