Bands of Acamarian exiles who left their homeworld a century earlier to escape its clan blood feuds and lived as nomadic marauders until the Enterprise-D brokered their return in 2366.
The Gatherers appear in the Next Generation episode The Vengeance Factor. They are Acamarians, not a separate species, descended from those who refused to accept the peace that ended centuries of clan warfare on Acamar III. For a hundred years they have roamed in ships, raiding outposts for supplies.
After an attack on a Federation science station, Picard persuades the Acamarian leader, Sovereign Marouk, to offer the Gatherers amnesty and a way home. A local chief, Brull, agrees to take the proposal to the overall leader, Chorgan.
The talks are shadowed by murder. Marouk's servant Yuta is the last of the Tralesta clan, massacred by the Lornaks eighty years before; her ageing has been slowed and she carries a microvirus fatal only to Lornaks. Riker, who has grown close to her, is forced to kill her as she reaches for Chorgan. The agreement is concluded.