The order came down on 10 March 1583 (new style) to Edmund Tilney, then the Master of the Revels; though Sir Francis Walsingham, head of intelligence operations for the Elizabethan court, was the official assigned to assemble the personnel.
[1] At that time the Earl of Sussex, who had been the court official in charge of the Lord Chamberlain's Men in its first Elizabethan incorporation, was nearing death.
The task of convening the new troupe apparently needed Walsingham's strong arm, since it was assembled by raiding the best performers from the companies existing at the time.
But it also signaled a new awareness on behalf of the Queen and the privy council of the potential for combining theatrical and espionage activities, since players frequently traveled, both nationally and internationally, and could serve the crown in multiple ways, including the collection of information useful to Walsingham's spy network.
But as John Stow wrote of this period in his Annals (1615): Comedians and stage-players of former times were very poor and ignorant...but being now grown very skillful and exquisite actors for all matters, they were entertained into the service of diverse great lords: out of which there were twelve of the best chosen, and...were sworn the Queen's servants and were allowed wages and liveries as Grooms of the Chamber.
The number of twelve founding members is more revealing than it seems at first: Queen Elizabeth's Men was the first large company of actors in English Renaissance theatre, twice the size of its predecessors.
The players in Sir Thomas More are "four men and a boy....") The size of the new company enabled it to act a new kind of play, built on a larger scale than ever before.
These were, in effect, the "Hollywood spectaculars" of their era, and represent a leap to a new level of complexity and professionalism; before the establishment of the Queen's Men, such plays would have been unactable.
John Singer completed his stage career with a decade with the Admiral's Men; the others toured the provinces and sold off their play books to London stationers.