According to earliest recorded accounts, the community of Black Yemenis known as the Muhamasheen, or the “marginalized,” have resided in Yemen since the sixth century. Yet, their position on the margins of Yemeni social landscape and their racialization as permanent outsiders challenges understanding of race and racialization in the Arabian Peninsula. Unlike other Black and non-Arab migrants to the Gulf, the Muhamasheen’s presence in Yemen is not a consequence of contemporary labor migration. Indeed, Muhamasheen identify as Indigenous Arab Yemenis. This historic presence disrupts our understanding of territory and identity. This paper explores the racialization of the Muhamasheen as permanent outsiders in a territory in which they have resided for centuries. It further demonstrates how non-Black Yemenis deployed imagined genealogies in this racialization process. The Muhamasheen experience contributes to a global history of race and reveals the gradations of Blackness (and the consequential gradations of anti-Blackness) that operate in the Gulf. Moving Yemen from the margins of Arabian Peninsula studies to its center allows for new ways to interrogate race and racialization in the region. This is because Yemen’s significant and historical links to East Africa and the broader Indian Ocean World allows us to reconceptualize the Gulf as spatially belonging to the same world as East Africa and South Asia. In this way, Yemen, and the Indigenous Black Muhamasheen in particular, help reveal a legacy of Blackness that does not only migrate to the Middle East but is woven into the very social histories of the region.