Your question is missing the name of the poem. After searching online, I've found it refers to "Verses Written by a Young Lady, on Women Born to Be Controll'd!", by Anonymous, in http://englishjessicajones.weebly.com/uploads/6/9/6/5/69653055/commonlit_verses-written-by-a-young-lady-on-women-born-to-be-controll-d.pdf
Answer and explanation:
The poem we are studying here expresses the perspective of a female speaker on being subservient to men. She is thoroughly unhappy with her position, describing it right from the start as the reason for her woes. She gradually shows how women are always subservient to someone: her father, her brother and, then, her husband.
<em>The tyrant husband next appears,
</em>
<em>With awful and contracted brow;
</em>
<em>No more a lover’s form he wears:
</em>
<em>Her slaves become her sovereign now</em>
<em>[...]</em>
<em>Yet love usurps her tender breast,
</em>
<em>And paints a phoenix to her eyes:
</em>
<em>Some darling youth disturbs her rest,
</em>
<em>And painful sighs in secret rise.</em>
<em />
<u>Taking the general context of the poem and the specific lines above, we can explain the meaning of the line </u><u><em>Her slaves become her sovereign now.</em></u><u> When a woman falls in love with a man, she does not anticipate that man will become just another boss of her, just another ruler in her life. Love deceives her; the man deceives her when he takes "a lover's form". He probably treats her kindly until the point when they get married. Then he goes from lover, from a slave to her beauty and affection, to her sovereign, someone who will make her as miserable as she was before marriage.</u>
