Portia is one of the main characters in the play, and we are introduced to her in name quite early in the play. Bassanio tells Antonio and audiences that he has his love sights set on Portia because she is super attractive and super rich.
In Belmont is a lady richly left,
And she is fair and—fairer than that word—
Of wondrous virtues. Sometimes from her eyes
I did receive fair speechless messages.
Her name is Portia, nothing undervalued
To Cato’s daughter, Brutus' Portia.
Apparently, she is so rich and so good looking that many men from around the world know about her and are trying to obtain her as their trophy wife.
Nor is the wide world ignorant of her worth,
For the four winds blow in from every coast
Renownèd suitors, and her sunny locks
Hang on her temples like a golden fleece,
Fortunately, Shakespeare creates a much more vibrant and deep character with Portia than a static, beautiful and empty headed character. Audiences will discover that Portia is incredibly intelligent and unafraid to go after what she wants. This is why she rigs the casket lottery to make sure that Bassanio picks the right casket. She's also intelligent enough to manipulate and twist the law in her favor in order to rescue Antonio out of Shylock