Swahili culture is the product of the history of the coastal part of the African Great Lakes region.
By the 8th century, the Swahili people became involved in the Indian Ocean trade. As a consequence, they were influenced by the Arab, Persian, Indian and Chinese cultures.
As well as in the Swahili language, Swahili culture has a Bantu core and has also borrowed foreign influences. This Bantu expansion introduced the Bantu peoples in central, southern and southeastern Africa, regions of which they were previously absent. They gradually evolved to accommodate an increase in trade (mainly with Arab traders), population growth and even more centralized urbanization, developing what would later become known as the Swahili city-states.
As we can see Arab settlers particularly influential along the Swahili coast because they were the Bantu's major trading partner.
This was a genocide committed by the Hutu majority government. They believe that the Tutsis are genetically inferior and without government opposition since Hutus hold the majority they were allowed to commit this genocide pretty much without consequence. Famous genocide because it was mostly committed with axes and machetes and was extremely barbaric
Germany and Soviet Union
(They did not declare war on the Soviet Union though)