What are the oldest landscape paintings?
I think the earliest will likely be Chinese ink paintings like this one (c.1000 CE). The earliest in the western tradition may be the Reformation era paintings of Pieter Bruegel the Elder (1565 CE). Art was so closely tied to religion, and was so iconographic in Europe prior to this that there was no “market” as it were for landscapes. Jan van Eyck was able to incorporate some realistic landscapes into his religious works as early as 1430.
In Western painting, it seems that you’re right to assume that pre-Renaissance painting didn’t much represent realistic mountainous landscapes. The oldest realistic (but not representing a real one) painting of a mountain is supposed to be in the background of The Virgin of Chancellor Rolin by Van Eyck (1435). The oldest actual alpine landscape painting is supposed to be The Miraculous drought of fish by Konrad Witz with the Mont Blanc valley in the background. Otherwise there’s Durer putting the Brenner mountains in the background of this self-portrait (1498).
