Elegies do not have to be only funeral poems: in ancient Rome “elegy” meant a poem written in a specific kind of metre, which could be about death as well as about love. For instance Ovid’s Amores are elegies. Donne dropped the metre requirement which would not have worked out in English and imitated Ovid in writing love elegies. Even though we’ve been taught for the last five decades or more to avoid biographical readings, I cannot help but read the poem through what we know about Donne’s troubled courtship of his future wife. The lovers depicted in the poem apparently have to keep their love a secret and they are in fear of the wrath of the lady’s father. Now the speaker has to go abroad and the lady has apparently formed a wild notion to accompany him dressed up as a boy page. (Some ladies apparently did attempt it.) The whole poem is the speaker’s attempt to talk her out of it.
The poem begins with a series of imploring requests, recalling all the troubled circumstances of their courtship: the necessity to hold back their love, spies and rivals, “thy father’s wrath” and so on. Now the poet uses all them to swear by them in order to ask his mistress not to do something that dangerous. She should stay back and remember him, and if she should die before he comes back, her soul is going to call his soul and he is going to die too. Her beauty is not mighty enough to calm the raging seas and she should remember the fate of Orithyia, whom Boreas, the god of north wind loved and inadvertently killed. (I don’t think it’s the most popular version of the myth.) Moreover, she should not dissemble anything, even with good intentions. Then Donne indulges in some national stereotyping, warning his lover that the notoriously amorous Frenchmen will recognize her as a woman and “know her” in the biblical sense, while the homosexual Italians will want to pursue her as boy. He does not specify what the Dutchmen will do to her except for calling them “spongy, hydroptic”, i.e. drinking all the time, so maybe his point is just that they are not pleasant to be with and she’s better off at home. England is the only gallery worth of her, through which she can walk until she is called to be presented at court. In the meantime, she still should hide her love, and especially don’t frighten her nurse with her nightmares about her lover being killed and dead. Instead she should foresee for him a better fate, unless God thinks having been loved by her was enough happiness for him.