Manuscript Type: EmpiricalResearch Question/Issue: This paper addresses the effect of having multiple large shareholders on shareholder protection. More specifically, we examine to what extent this effect depends on whether such large shareholders are beneficiary or fiduciary. Research Findings/Insights: Analyzing longitudinal, hand-collected data covering Swiss listed companies, we find that having several large shareholders leads to overall higher shareholder protection (i.e. adoption of more formal corporate governance mechanisms). This is because large shareholders have an interest in putting more formal governance mechanisms in place when there is another large shareholder that might try to extract rents at the expense of others. Moreover, we find that this effect is driven by the presence of several beneficiary shareholders, i.e. shareholders that invest their own wealth in the company in contrast to dispersed ownership and fiduciary shareholders, i.e. shareholders acting on behalf of others. Theoretical/Academic Implications: Building on recent developments in agency theory, this paper contributes to the corporate governance literature by empirically showing that potential "principal-principal" conflicts among large shareholders lead to overall better shareholder protection in terms of more formal governance mechanisms being adopted. This finding contrasts with situations in which there is only one large shareholder that does not have an interest in strengthening formal corporate governance. Our findings imply, however, that the characteristics of the large shareholders matter: Fiduciary shareholders in the Swiss setting are mostly passive buy-and-hold shareholders and therefore do not engage extensively in improving shareholder protection. Beneficiary shareholders, in contrast, directly intervene in the governance of the firm (i.e. governance by voice), so that in the presence of multiple beneficiary shareholders, more formal governance mechanisms help to monitor not only management but the other large shareholders as well. In addition, more formal governance mechanisms serve as a platform to coordinate their diverging objectives. Practitioner Implications: We demonstrate the influence of a second (or several) large beneficiary shareholder(s), on corporate governance and the benefit to all shareholders. In addition, we propose the strengthening of governance mechanisms as a platform to reconcile conflicting interests among prominent shareholders and contribute to the debate on the allocation of certain voting privileges to long-term shareholders.