When Pope Benedict XVI stepped down from the Petrine ministry on February 28, 2013, and Francis was elected pope on March 13 of that year, a totally new situation was created, one not previously known in the history of the papacy and the Church. We still lack dogmatically adequate ways of understanding and expressing it. On the one hand, we must avoid the heretical idea of dual leadership (as in speaking about "two popes"), and on the other hand we must recognize the fact that -- according to current parlance -- there is an "emeritus" pope, a Bishop of Rome who no longer holds the Petrine office. The problem is that the Bishop of Rome as successor of Peter constitutes the principle of unity, which can only be realized by one person. In reality there can only be one pope, which means the terminological distinctions between a "current" and a "retired" pope, or between an active holder of Roman primacy and a passive participant in it, are not helpful.