The first English patent for a method of making colored glass was granted in 1449.
King Henry VI granted the patent to John of Utynam, a skilled glass-maker from Flanders. Utynam had come to England to produce stained-glass windows for Eton College. His grant gave him a 20-year monopoly over making stained glass, an unusually long commercial privilege for the period.
This patent is often described as England’s first known patent, rather than necessarily the first patent ever issued in England. Earlier patent-like privileges existed elsewhere: Venice, for example, granted protections to glass-makers during the early 1400s. The 1449 grant is important because it clearly connects royal privilege with a specific manufacturing technique and inventor.
A common mix-up is confusing this date with later patents for industrial glassmaking. The 1449 document concerned stained or colored glass, not modern transparent glass production, window technology, or a trademark for a glassmaker.