<p>We discuss the correspondence between highly excited strings and black holes in the presence of angular momentum. At fixed imaginary angular velocity <i>ν</i>, we show that free strings exhibit a Hagedorn instability due to a thermal-winding mode turning tachyonic. This allows us to determine the exact Hagedorn temperature <i>β</i>_<i>H</i>(<i>ν</i>) for bosonic, type II, and heterotic strings. Using the effective field theory for the thermal-winding mode around the <i>ν</i>-dependent background, we find a novel ‘rotating string star’ saddle (perturbatively in the angular velocity) and study its properties. This configuration describes a self-gravitating bound state of highly excited rotating strings. As in the non-rotating case, the saddle is qualitatively shown to interpolate between the rotating strings phase and a rotating black hole. We also comment on the implications of these results for anti-de Sitter space.</p>