Patroclus is a Greek commander and Achilles' BFF / not-so-secret lover. (Yeah, we know Achilles is engaged to Polyxena but ancient Greek men were known to have male lovers, even if they were married, engaged, or otherwise in with the ladies. If anything, the guys' relationship is a reminder that male bonds trump heterosexual romance in the world of this play.)
As we know, the other Greek commanders hate Patroclus and they make a huge deal out of the fact that Achilles won't come out of his tent and fight. In fact, they say that Patroclus is the reason the once mighty Achilles has become "dainty of his worth" (soft and effeminate) because the two guys spend all their time "upon a lazy bed" (1.3.145-147). So, the Greek military commanders definitely see Patroclus as a threat. But is it really true that he's a distraction to Achilles?
As it turns out, Patroclus is the reason Achilles will even get out of the tent and back on the battlefield. When Hector kills Patroclus, Achilles is so enraged that he and his Myrmidon henchmen roar onto the battlefield and slaughter Hector, which is a huge blow to the Trojan army. Plus, we later find out that Achilles had promised his girlfriend that he wouldn't fight, which means that maybe Patroclus wasn't the real distraction after all.
So, what is it about Patroclus that is so threatening to the Greek commanders?
Well, for one thing it turns out that the guy is also quite the comedian and spends a lot of time doing hilarious impersonations of the leaders. Check out what Ulysses has to say about it:
Upon a lazy bed the livelong day
Breaks scurril jests;
And with ridiculous and awkward action,
Which, slanderer, he imitation calls,
He pageants us. Sometime, great Agamemnon,
Thy topless deputation he puts on,
And, like a strutting player, whose conceit
Lies in his hamstring, and doth think it rich
To hear the wooden dialogue and sound
'Twixt his stretch'd footing and the scaffoldage,—
Such to-be-pitied and o'er-wrested seeming
He acts thy greatness in: (1.3.146-158 )
Ahh. Now we get it. The leaders hate Patroclus because he's got no respect for them. Here, Ulysses complains that Patroclus acts like a "strutting player" (i.e. an actor who struts across the stage) when he imitates the Greek commanders and makes fun of them.
Thing is, "strutting player" is a phrase often used to describe Elizabethan actors. Come to think of it, Patroclus is a lot like the Shakespearean actors performing in this very play. What's up with that?
If we think about it, Troilus and Cressida is all about making fun of the so-called heroes from classic mythology and literature, right? And it's full of professional actors impersonating these heroes on the stage. So, when we hear that Patroclus spends all his time entertaining Achilles by "pageant[ing]" the Greek leaders, Shakespeare reminds us that we are in fact watching a play by professional actors whose job it is to impersonate these same figures from literature and mythology.
Is your mind blown? Just a little?
Here's our theory: Shakespeare is drawing our attention to the relationship between theater and rebellion. Patroclus' theatrical play-acting is threatening because it criticizes important political and military figures. As it turns out, Elizabethan playwrights and actors could also get into a lot of trouble for criticizing and making fun of important political and military leaders (like the queen, for example) on stage, which is why government officials were always censoring plays.
So when Pandarus messes everything up—is he really messing everything up? Or is he just exposing how ridiculous all of our heroes and heroines really are?