Apprenticeship was a key feature of early modern playing companies, yet it is easily misunderstood by modern observers. The development of apprenticeship in Elizabethan England paralleled the development of trade guilds, more properly known in London as livery companies. Male apprentices were important because they played all the female roles on the professional English stage before 1660, but the institution also served as a training ground, with many (perhaps most) theatrical apprentices going on to become adult players. In this sense, theatrical apprenticeship was much like apprenticeship in more traditional trades, and the similarities became more notable as the professional theatre became more stable and structured. In fact, many professional players were members (or freemen) of the livery companies that collectively oversaw most of the trades in London, and theatrical apprentices were often formally bound as goldsmiths, grocers, drapers, or some other trade, even when all their training was on the professional stage.