In a landmark decision, the Muscogee (Creek) Nation supreme court ruled that Rhonda Grayson and Jeffrey Kennedy, two descendants of people who were once enslaved by the tribe, are entitled to tribal citizenship.

The court ruled on Wednesday that the Muscogee Nation’s citizenship board violated a 1866 treaty in denying Grayson and Kennedy’s 2019 application for enrollment. At the time, the citizenship board argued that the descendants should be denied because they could not identify lineal descendants of the tribe.

Grayson, who is the founder and director of the Oklahoma Indian Territory Museum of Black Creek Freedmen History, and Kennedy are descendants of the Creek Freedmen, people who were enslaved by the Muscogee Nation. They can trace their lineage back to people who are on the Dawes Rolls, a list that identifies people from the Cherokee, Chickasaw, Choctaw, Muscogee (Creek) and Seminole tribes. Grayson’s and Kennedy’s ancestors are also listed on the Freedmen Roll, but not the Muscogee Roll. This discrepancy is how the tribal citizenship board previously justified denying Grayson’s and Kennedy’s applications for enrollment.

However, the court ruled unanimously this week that such a decision was in violation of the Muscogee Nation’s laws. “Are we, as a Nation, bound to treaty promises made so many years ago?” the court wrote. “Today, we answer in the affirmative, because this is what Mvskoke law demands.” According to the ruling, any future applicant who can trace their ancestry to someone on either roll will be eligible for enrollment.