Reorganization of the Asian climate from one dominated by global planetary wind systems to a regional monsoon climate is closely related to the surface uplift of the Tibetan Plateau (TP). However, evaluating this climatic reorganization is limited by difficulty in constraining the complex, multistaged uplift of the TP and contradictory evidence regarding Asian Monsoon onset. In this Review, we summarize proxy and model evidence for Asian Monsoon initiation at different latitudes to identify the main controls on monsoon evolution. Stratigraphy and palaeoclimate proxy records indicate that the Asian climate was reorganized in a two-stage northward expansion process. At ~41 million years ago (Ma), the monsoon advanced northwards from the tropic to the southern subtropical regions (~26° N, approximately present-day Yunnan), probably driven by central TP uplift, global cooling and rapid regression of the proto-Paratethys Sea. At ~26 Ma, the monsoon expanded northwards into temperate regions (~30–36° N, equivalent to the present-day Asian Monsoon boundary), likely driven by TP growth and global warming. Additional proxy records are needed to fill regional gaps, establishing more solid boundary conditions and improving parameter constraints for climate models.