In this symposium I will outline recent results demonstrating how the activity levels of solar-type stars evolve over time, affecting the environments in which planetary systems themselves evolve. As solar-type stars form, they interact with large circumstellar discs, setting the conditions in which fledgling planetary systems are born. In much older billion-year old systems, stellar activity levels have significantly decreased, but the host star’s spectral type plays a critical role in determining the kind of environment in which their planetary system is embedded. I will give an overview of how G-M-type stellar magnetic fields evolve, and how the same data used to detect and characterise stellar magnetic fields can also be used to robustly detect and characterise exoplanet signatures that are at or below the level of the stellar variability.