The now completed HERES (Hamburg ESO R-process enhanced stars) survey
has collected a database of UVES observations for over 300 metal poor stars,
i.e. the largest sample so far of high resolutions spectra for such objects.

In the talk I will present the analysis of the C-rich metal poor stars in
HERES, discuss their fraction, the possible formation scenarios and the
constraints they supply for stellar evolution at low metallicity as
well as the Initial mass function in the early Galaxy.