Abstract. A large majority of the direct observational record for glacier changes falls within the post-industrial period, associated with global glacier retreat. Given this availability of data, and significant focus in contemporary glacier modelling falling on post-industrial retreat, glacier models are typically calibrated using – and validated with – only observations from points where glaciers were considerably out of equilibrium. In order to develop a broader picture of the skill of one glacier model in active development – the Open Global Glacier Model (OGGM) – we model glaciers for extended historical timescales of 850–2004 CE using a selection of 6 climate model outputs, including recent post-industrial history. We select glaciers for which long term glacier length observations are available, in order to compare these observations with the model results, and we find glaciers for this purpose in almost all glacierised regions globally. In many regions, the modelled glacier changes are consistent with observations, with recent retreat often as rapid as – or sometimes more rapid than – modelled retreats. We also model this set of glaciers using modified climate timeseries from each of the 6 climate models to keep temperature or precipitation constant, testing the impact of each individually. Temperature typically explains considerably more variance in glacier lengths than precipitation, but results suggest that the interaction between the two is also significant within OGGM and neither can be seen as a simple proxy for glacier length changes. Overall, with the vast majority of glaciers successfully modelled, and recent observational trends in many regions reproduced by the model running over a considerably larger timescale than it is calibrated for, prospects are good for more widespread use of OGGM for timescales extending to the pre-industrial, where glaciers are typically larger and experience less rapid (and less globally consistent) geometry changes.