Between 300 BCE and 1800 CE, Indian Ocean commerce was managed by traders who bridged exchange networks across the edges and peripheries of empires and interaction spheres through trader alliance networks (TAN). Using Network Theory, we hypothesize that TAN were characterized by high Triadic Closure and relatively little political influence between 300 BCE–1400 CE, and shifted to Brokerage and high political influence after 1400 CE. These shifts and their impacts are tested through archaeological data from the Indian Ocean ports of Chaul, India, and Mtwapa, Kenya. These shifts enable understanding
the emergence and impact of trader lobbies, pressure groups, and ‘Great Firms’ as global power brokers, and the rise of Predatory Commerce after 1600 CE that continues to this date.