We report on the discovery of a very distant galaxy cluster serendipitously detected in the archive of the XMM-Newton mission, within the scope of the XMM-Newton Distant Cluster Project (XDCP). XMMUJ0044.0-2033 was detected at a high significance level (5σ) as a compact, but significantly extended source in the X-ray data, with a soft-band flux f(r < 40″) = (1.5 ± 0.3) × 10-14 erg s-1 cm2. Optical/NIR follow-up observations confirmed the presence of an overdensity of red galaxies matching the X-ray emission. The cluster was spectroscopically confirmed to be at z = 1.579 using ground-based VLT/FORS2 spectroscopy. The analysis of the I − H colour − magnitude diagram shows a sequence of red galaxies with a colour range [3.7 < I − H < 4.6] within 1′ from the cluster X-ray emission peak. However, the three spectroscopic members (all with complex morphology) have significantly bluer colours relative to the observed red-sequence. In addition, two of the three cluster members have [OII] emission, indicative of on-going star formation. Using the spectroscopic redshift we estimated the X-ray bolometric luminosity, Lbol,40″ ~ 5.8 × 1044 erg s-1, implying a massive galaxy cluster. This places XMMU J0044.0-2033 at the forefront of massive distant clusters, closing the gap between lower redshift systems and recently discovered proto- and low-mass clusters at z > 1.6.