Direct democracy can be seen as a kind of system where citizens directly discuss and vote on the main issues of interest. This kind of democracy arose in Ancient Greece, where popular assemblies assembled the population of democratic city-states in the Agora (square), where laws and key decisions were discussed and resolved. Remember that in the Greek way, the exercise of political opinion was restricted to a specific portion of the population.
Buganda had a good climate with reliable rainfall with fertile soils which ensured constant supply of food for the population and army. Due to increased population there was need for more land hence expansion of the kingdom. Buganda's dealings with Arabs enabled her get guns.