Azorius Senate
The Azorius Senate is a guild from Ravnica and featured in Dissension. They are the guild themed of the colors of blue and white. In the city, their purpose is to create laws and ensure that everyone abides by them. The parun was Grand Arbitrer Azor I, who wrote most of the original Guildpact.
The Azorius work with the Boros Legion and the Selesnya Conclave to enforce the law, and the Orzhov Sindicate provides advocates and law mages as defendants or accusers.
During most of the Ravnica storyline, it is presided by the human lawmage, Grand Arbiter Augustin IV. After his death, the new guildmaster is named Leonos II.
They are technically the ruling government of Ravnica.