In 1889, the Glasgow architecture company Honeyman & Keppie hired Mackintosh to work as a draftsman but moved his way up and became a partner. In 1897, the firm won the competition to design the new Glasgow School of Art based on Mackintosh's designs. With its rectilinear emphasis, clean rows of windows bordered in bold black lines and curving entrance details, the school blends into the Glasgow Style perfectly.
In 1900, Mackintosh was invited to present his exhibition in the 8th Vienna Secession (an important modern art show in Vienna). Along with the other members of The Four, he designed a room interior and all the furnishings, including wall paneling, light installations, furniture and decorative arts. Their inclusion gave a wider audience for their work.
Mackintosh was a strong believer that art and design should encompass the whole - it wasn't enough to design a single object, or picture, or light fixture. Everything should work perfectly together. His work in Architecture and Interior Design demonstrates this belief.
In 1901, Mackintosh and his wife entered a contest held by a German design magazine to design a House for an Art Lover.