Charles Rennie Mackintosh (1868–1928) was a pioneering Scottish architect and designer whose furniture and interiors helped define the transition from the Arts and Crafts movement to early modernism. A leading figure of the Glasgow Style, Mackintosh developed a uniquely personal aesthetic that combined crisp geometry, elongated forms, and subtle symbolism. Working closely with his wife, Margaret Macdonald, he created holistic interior schemes where architecture, furniture, and decoration were conceived as a unified whole. His high-backed chairs, delicate inlay work, and carefully proportioned designs emphasized both structural clarity and refined craftsmanship. Notable commissions such as the Willow Tea Rooms and Hill House demonstrate his ability to blend functionality with poetic form. Although his work was not widely recognized during his lifetime, Mackintosh’s influence grew in the 20th century and established him as a key precursor to international modernist design.