From SuspireWiki

The Herald is the Overlord’s mouthpiece. When the Overlord makes a decree, the Herald’s job is to make sure that all of the cities in the Hold and the Kindred within them hear of it (assuming it’s meant for all ears…). When the Overlord convenes a court, the Herald is responsible for alerting those who must attend. The Herald hands down judgment, represents the Overlord in proxy when she cannot (or will not) make a personal appearance, and otherwise serves as something of a “secretary of state.” The Herald is assumed to speak with the Overlord’s voice at all times. Some treacherous or ambitious Heralds use this fact to direct other Kindred to their own liking, making suggestions that others assume carry the weight of the Overlord’s orders. Some Heralds who were less subtle than they believed have been executed for this very thing, so wise Heralds remain more or less honest.

The Herald position is a Hold level position, however large Holds may have more than one Herald.

Five things a Herald May Do

• Deliver messages personally to a Prince's Elysium at behest of the Overlord
• Inform Princes that they have been summoned by the Overlord
• Represent the Overlord at ceremonies he doesn't wish to attend personally
• Bring news of a new dictate from the Overlord or King to a city
• Make a casual suggestion as to something the Overlord would probably like to see (...even if the Overlord never said so)