Like many of the OUP "Very Short Introduction" series, you can't really tell what the book is about from the title. This is not a survey of African history, but rather a survey of how historians, political leaders and others have interpreted African history. E.g., colonialists created an African history -- or pretended there wasn't one -- that would best serve the cause of colonialism. That is, if Africa is seen as a land of primitive, savage tribes, the colonial powers could defend their actions as just spreading civilization. Conversely, post-colonialists have often created a nationalistic view of African countries that did not exist prior to the European powers marking arbitary lines on their maps.
The authors take pains to note that any statement about Africa as a whole is likely an over-generalization. The history of the Congo area, for instance, is considerably different from that of South Africa. Yet, as diverse as the regions are, the authors assert that the concept of "Africa" shouldn't be abandoned.
The whole subject of African history is a difficult one for historians, or anyone, because of the lack of sources. What we know of African cities like Timbuktu is essentially what travelers wrote about them. Often, the African climate has worked to eradicate the records of what might have been there prior to 19th century European colonization. Even oral history is suspect, as oral histories are subject to change over time. This makes it difficult for those attempting to decolonize Africa to actually figure out what a particular African region was like prior to colonization. For once colonization began, the nature of the region might have changed drastically. For instance, the 1996 Rwanda genocide of the Hutu against the Tutsi is not, as depicted in Western media, a struggle between two tribes. The difference between the Hutu and the Tutsi -- genetically the same -- entirely stems from how these people were treated by German and Belgian colonialists, creating an artificial division between them that continued and worsened even after the Europeans were long gone. (It occurs to me as I write this, that this is somewhat similar to the aftermath of Ottoman colonization of Southern Slavs.)
But while African history can't escape concentrating on the effects of colonialism, the authors cover other areas, e.g., the participation of African states in the slave trade -- possibly as many slaves went East as went across the Atlantic, and many slaves were transferred internally only. African history can't be discussed without discussing the slave trade, but the authors warn that there was a lot going on at the time not related to the slave trade, so it's a mistake to think of Africa as a continent of victims.
History has always been more about interpretation than facts, and that's particularly true in the case of Africa.
If you plan on reading any African history, or just want to understand the background of current African political issues, this book will provide needed perspective.