It is believed that the origins of tennis can be traced to 12th century French monks who volleyed the ball with their hands in indoor courts. By the 16th century, racquets with long handles, small wooden frame heads, and strings made of intestines, came into use. It wasn't until 1874 that modern, outdoor tennis - then referred to as "lawn tennis" - and its equipment were patented by Walter Wingfield in London. He introduced and sold solid wood tennis racquets which led to the laminated wood racquets, iconic of the 1950s - early 1970s. These laminated racquets were most often glued layers of ash, maple, sycamore, and hornbeam. In later models, manufacturers included non-wood materials in the laminate. Though metal racquets have replaced the wooden frames, the leather handles and multicolored frames of the past still evoke a weekend at the courts.