Great leaders are also managers. Contrary to many statements and beliefs this article goes on to argue that great leaders often do NOT consider the management duties/responsibilities as below their level. In fact they actively participate. This is what makes them great leaders- as they know the intricacies of the businesses they are in and are able to relay the right and doable strategy and vision to their teams.
http://blogs.hbr.org/cs/2010/08/true_leaders_are_also_managers.html