Gulliver is accused of high treason after defeating the fleet of Blefuscu, an island near Liliput that is in war with them because of the way each one break eggs. It´s an analogy of the confrontation between liberals and conservatives parties that was passing on the England of the times.
The Blefuscu´s people sustained the primitive way of breaking eggs, by the wide end while the Liliput´s population had introduced the novelty of breaking it by it´s narrow end. Gulliver is on behalf of Liliput at first and helped them to win the war but then he denies to turn the Blefuscu island into a province of Liliput upsetting this way the King and the court.
After this Gulliver is visited by a "considerable person at court" who tells him that his mortal enemy Skyresh Bolgolam, an almirant that have seen his fame obscured because of Gulliver´s success, the high-treasurer Flimnap, the general Limtoc, the chamberlain Lalcoln, and the grand justiciary Balmuff have prepared an article accusing him of treason and other capital crimes in a four articles writting.
The first article accused Gulliver of make watter within the precints of the royal palace; it was forbidden but Gulliver did it to save the imperial consort after a fire started.
The second article is about the denial of Quinbus Flestrin; as the Liliput people have named Gulliver; to turn Blefuscu into a province and kill those who stood against.
The third article reproach Gulliver´s attitude with the Blefuscu´s ambassadors that arrived to the island asking for the peace. He helped and sponsored them.
And finally the fourth article said that he was preparing a voyage to the Blefuscu empire and that he only get a verbal permission from the king to do that.
I hope the answer help you. Regards.