A few richly decorated wooden painted reliquary shrines used to preserve sacred relics are still listed and preserved in Belgium. Fourteen of these painted reliquaries survived the violent iconoclastic attacks of 1566. Their veneration ensured monasteries and churches a reputation and prosperity linked to pilgrim visits. After 500 years of intensive use and multiple modifications, ten of them can still be found in the churches for which they were originally fabricated. Despite their obvious historical importance and often worrying prospects for the future, these Belgian reliquaries have been little studied. Knowledge of painted shrines is insufficient compared to neighbouring countries. Within the PaReS project (Painted Relic Shrines in Situ), wood has been the subject of extensive research alongside studies of other materials and techniques, as well as the function and use of these painted reliquaries. Many questions arise when studying these enigmatic objects, as little is known today about how they were made, where they were manufactured, and who made them. Their manufacturing technology, symbolic meaning, ritual uses, location in the church, complex mix of materials, current condition, value and significance, as well as future conservation options, all need to be examined. This research work has taken an interdisciplinary approach, combining art history research with cutting-edge scientific investigations to address the question of the dating, provenance and physical evolution of the materials, with wood playing a central role. Dendrochronology in particular had to adapt to the possibilities of access to growth rings, moving from traditional macro-photography recordings to tomography recordings, but also confirming certain “surprising” dendrochronological results with radiocarbon dating (14C). These results were compared with other findings: high-resolution photographs, advanced imaging (IRR, XR, MA-XRF, 3D scans) and chemical analyses. For centuries, reliquaries have occupied a central place in society. The aim of these studies is to reconnect these objects with their (sometimes forgotten) past in order to ensure their future.