ABSTRACT Sparsely populated geographic edges of colonised nations exhibit heterogenous historical demographic trajectories. In this study, we analyse the longitudinal evolution of the settlement system in Northern Australia to quantify and visualise relative settlement dynamics over 165 years. We extend the existing literature by deviating from analysing each township as an individual entity, instead focusing the analysis on relativities within the entire settlement system. We quantify settlement and systemic volatility through measurement and visualisation of relative settlement sizes using rank-sizes and document rank-size changes between 1856 and 2021. We analyse rapid and non-synergic shifts in rank-trajectories and demonstrate rank-trajectories for selected settlements by types. We found that the expansion of a fly-in-fly-out workforce in the resource sector since the 1980s has meant less turbulent trajectories for the settlement system in the North could potentially open prospects for more sustainable population growth policies while relocating the risks of resource dependency in employment and growing unemployment during economic bust from edges to core areas. Beyond annotating the evolution of the settlement system in Northern Australia, this study demonstrates the potential for policy, economic conditions and definitional peculiarities to affect volatility in the settlement system at geographic edges elsewhere.