By July 14 Cuesta had drawn up the Spanish force near Medina de Rio Seco, with Blake commanding the forward position on a small elevation and Cuesta hovering about a mile to the rear (near the village proper), with many of the best troops.
Bessières, well-informed of the Spanish plans by virtue of an enterprising double-agent, advanced from Burgos July 9 in the aim of preventing Blake's junction with Cuesta, resolving to concentrate his effectives en route.