Monsoons are among the most significant weather phenomena and climate systems on Earth, profoundly impacting both the natural environment and human societies. The dance between wind and precipitation have been vital to the development, sustenance, and even collapse of civilizations throughout history. Despite considerable progress in understanding the history and evolution of monsoon subsystems over the past few decades, critical questions remain unanswered. For instance, how are monsoon systems coupled or decoupled, and how do they interact with regional and global climate dynamics? These complexities challenge our understanding of the feedbacks between monsoons and other components of the climate system. This research theme invites studies on past monsoonal changes, integrating evidence from both continental and marine archives across all major monsoon subsystems—Asian, African, Australian-Indonesian, and North and South American monsoons—spanning diverse timescales, from tectonic and orbital to millennial, centennial, decadal, and seasonal. Contributions using modeling approaches and simulations are also encouraged, as they help bridge the gap between past variability and future projections. By unraveling the dynamics of past monsoonal systems, this theme aims to improve predictions of their behavior in a warming world.