After the Pact of Horodlo, Lithuanian boyars were given the same privileges as these people.
Members of this group claimed to be descended from the ancient race of Sarmatians. The passage of "Nihil novi" strengthened their position, as it prevented any new laws from being made without their approval. Their power was further increased through the Henrician Articles, which required all kings of these people to be elected and remain accountable to them. After the Pact of Horodlo, Lithuanian boyars were given the same privileges as these people. Those privileges included liberum veto, the ability of any of these people to nullify any measures passed during a session of their political council. For 10 points, name this class of people who lost much of their power after their commonwealth's partition.
Members of this group claimed to be descended from the ancient race of Sarmatians.
{Szlachta} (or {Polish}-Lithuanian {nobles}; or obvious equivalents; prompt on {Poles})