Patek Philippe introduced the Twenty~4 line in 1999 as mechanical watches were truly taking hold yet most ladies models were still quartz driven. The Twenty~4 line gave Patek Philippe a high-end style in the ladies market to rival models from Cartier (such as the Tank) and emerging jewelry brands. It was a successor to the successful (and continued) Patek Philippe Gondolo line which had existed since 1993.
The original Twenty~4 model was “bracelet style” with a rectangular head nearly as narrow as the bracelet. This integrated look provided space for two rows of diamonds on the vertical bezel, with the body of the watch protruding just a bit further. Most Twenty~4 models were simple, with two hands and a quartz movement. Patek Philippe produced a wide variety of styles using this same basic case design. One notable version is a diamond paved version with the mechanical Cal. 16-250.