The analysis of quaternary successions of the Himalayan Foreland basin suggests that tectonics, climate and glacial eustasy have influenced valley architecture and floodplain in different parts of the Ganga plains. Tectonic and climatic effects are involved in the formation of the valley near the Himalayan front, where major faults are active. The climate was an important factor near the craton margin in the western plains, where tectonic activity is lower and subsidence rates are moderate. Age models for this region suggest that discontinuity-bounded sequences were formed on time scales of 10 3 to 10 4 years in response to variations in monsoon and liquid precipitation and sediment discharge in rivers. Modern megavanes and rivers interfere with the eastern plains are not subscale, probably due to high sediment yields, low unit current power and high subsidence rates. Although long-term records are scarce, discontinuities are probably rare in this area. The channels in the Ganga-Brahmaputra delta are not currently subscales, but sea-level fluctuations generated thick Pleistocene valley fillings that extend several hundred kilometers inland. Many Himalayan and cratonic rivers throughout the area experienced the early incision of the Holocene in response to the monsoon intensification after the last glacial maximum, and brought a large sediment charge to the delta and Bengal fan. Many sections in axial parts of the Ganga system appear to have progressively migrated southward in the recent past, generating cliffs along their southern valley margins. This systematic migration reflects the collision of India and Asia and the consequent rise on the Himalayan front. Climatically controlled sequences may overlap this long-term migration of the valley, which should generate diachronic basal-base surfaces. The valleys in the interior alluvial plains can range from prominent to subtle in short periods and over distances of hundreds of kilometers, as well as periodically avulsing and migrating systematically.