This study empirically examines the dynamics of co-leading siblings in family firms. The findings were generated from qualitative interviews with 13 family firms of which nine are currently and four cases were once co-led by siblings. The research revealed that successfully and sustainably co-leading a family business as siblings can be considered as the king’s class of leadership as it includes managing the family layer with at least as much attention as the business layer itself. Besides diversifying in qualifications, competences, personalities and distribution tasks accordingly, processes such as the active and conscious decision-making for the business and at the same time for the co-leadership with other siblings are increasingly important to form a successful sibling team.