This thesis presents investigations of nonlinear light propagation dynamics in isotropic self-focusing materials. The first half of this thesis is devoted to studying the transverse spatial dynamics of optical vortices, donut-shaped beams with helical phase fronts. The second half of this thesis describes the spatiotemporal dynamics of sequential plasma filaments that are formed by high-peak power laser pulses. The objective of these studies is to identify novel behavior, to predict nonlinear trends, and to achieve a new understanding of the physical processes that govern the dynamics of high-power beams and pulses.