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Understanding Arctic glacier sensitivity is key to predicting future response to air temperature rise. Previous studies have used proglacial lake sediment records to reconstruct Holocene glacier advance-retreat patterns in South and West Greenland, but high-resolution glacier records from High Arctic Greenland are scarce, despite the sensitivity of this region to future climate change. Detailed geochemical analysis of proglacial lake sediments close to Zackenberg, northeast Greenland, provides the first high-resolution record of Late Holocene High Arctic glacier behaviour. Three phases of glacier advance have occurred in the last 2000years. The first two phases (c. 1320-800cal. a BP) occurred prior to the Little Ice Age (LIA), and correspond to the Dark Ages Cold Period and the Medieval Climate Anomaly. The third phase (c. 700cal. a BP), representing a smaller scale glacier oscillation, is associated with the onset of the LIA. Our results are consistent with recent evidence of pre-LIA glacier advance in other parts of the Arctic, including South and West Greenland, Svalbard, and Canada. The sub-millennial glacier fluctuations identified in the Madsen Lake succession are not preserved in the moraine record. Importantly, coupled XRF and XRD analysis has effectively identified a phase of ice advance that is not visible by sedimentology alone. This highlights the value of high-resolution geochemical analysis of lake sediments to establish rapid glacier advance-retreat patterns in regions where chronological and morphostratigraphical control is limited.