As a dramatic monologue, Browning’s poem features a narrator who speaks in the first person and describes an event that has just recently taken place. The speaker is the titular lover of Porphyria, and midway through the poem he describes himself as “one so pale / For love of her” (lines 28–29). Yet for all that the speaker may love Porphyria, he also feels frustrated by her. He initially makes this frustration apparent in his opening description of the storm raging outside (lines 1–5):

     The rain set early in to-night,
            The sullen wind was soon awake,
     It tore the elm-tops down for spite,
            And did its worst to vex the lake:
            I listened with heart fit to break.

These lines set the scene, introducing an atmospheric disturbance that vexes the speaker as much as it vexes the lake. Yet it soon becomes clear that what’s truly bothering the speaker isn’t the violence of the wind, but rather the violence of his passion for Porphyria, which Porphyria herself doesn’t fully return. Indeed, Porphyria cannot fully reciprocate his passion, since her love affair with him is an illicit one. The speaker must therefore “[find] / A thing to do” (lines 37–38) to resolve this imbalance of passions. His solution is to kill her. By doing so, he believes that he’s helping Porphyria fulfill her “darling one wish” (line 57) to give herself over to him completely.

The speaker presents the reasoning behind his actions in a logical way, as though the decision to murder his lover were perfectly rational. Yet the speaker’s reasoning is clearly deluded. For example, he presents his decision to murder Porphyria as a matter of granting her greatest wish, which was to submit herself to him entirely. Since her “pride” and “vainer ties” (line 24) kept her from fulfilling this wish herself, he took matters into his own hands. But in claiming that his actions were meant primarily to benefit Porphyria, the speaker fails to acknowledge his own desires for possession and control. These desires become clear in the logic that leads to the moment of strangulation (lines 31–38):

     Be sure I looked up at her eyes
            Happy and proud; at last I knew
     Porphyria worshipped me; surprise
            Made my heart swell, and still it grew
            While I debated what to do.
     That moment she was mine, mine, fair,
            Perfectly pure and good: I found
     A thing to do

The speaker sees something worshipful in Porphyria’s regard for him. This interpretation of her gaze convinces him that “she was mine, mine.” The repetition of “mine” here strongly implies that what the speaker has wanted all along is for Porphyria not simply to love him, but to belong to him. Thus, he arguably decides to kill Porphyria not to fulfill her wish, but to fulfill his own.