Onyeka is the author of Blackamoores: Africans in Tudor England, their Presence, Status and Origins, a groundbreaking publication that unearths the hidden history of African people in Tudor England and Scotland. The research in Blackamoores highlights the contribution African people made to the development of cities such as Edinburgh and challenges the commonly held belief that these people were slaves or placed at the lowest rung of society.

In his groundbreaking book, Onyeka argues that African people were present in cities and towns throughout England, but that they did not automatically occupy the lowest positions in Tudor society. This is important because the few modern historians who have written about Africans in Tudor England suggest that they were all slaves, or transient immigrants who were considered as dangerous strangers and the epitome of otherness. However, this book shows that some Africans in England had important occupations in Tudor society, and were employed by powerful people because of the skills they possessed. These people seem to have inherited some of their skills from the multicultural societies that they came from, but that does not mean all of those present in England were born in other countries: some were born in England.

 The arguments in this book are supported by evidence from a variety of  sources both manuscript and printed, most of which has not been widely  discussed – whilst some of it Onyeka has discovered, and this may be the first  time that it has been revealed. Other evidence is taken from texts that are the  subject of popular discussion by historians, linguists and so on, but Onyeka  encourages the reader to re-examine these works in a different way because  they reveal information about the presence, status and origins of Africans in  Tudor England.