•Hydraulic nature of bricks with low shrinkage and high mechanical strength.•Geochemical composition showed siliceous nature of monumental bricks.•Mineralogical analyses showed firing temperature ~900 °C under oxidising conditions.•The monumental bricks showed use of traditional indigenous production techniques. The historical monumental bricks dated 14–18th century CE of Haryana region of the Indian subcontinent were examined to assess their geochemical characteristics, and to understand the raw materials and production technique used in the brick manufacturing.The results showed that the bricks were foundhydraulic in naturewith low shrinkage and high mechanical and physico-sintering properties, containing high concentration of silica and low concentration of calcium.The combined results of applied methods (XRF, XRD, FTIR, TGA, and SEM) suggest that the bricks werefired at temperatures around 900 °C,underoxidising conditionsthrough traditional brick manufacturing technology.The observed variability in the bricks corresponds to different construction phases of monumental structures.These results also revealed thegeochemicalnature of raw materials and durability of monumental bricks, subjected to various types of weathering phenomena in aggressive environments of the Yamuna River basin. This reference work hasanimportant scientific value for the restoration and conservation of historical monuments with respect to longevity and durability of brick masonry.