The Commedia dell' Arte
Though not a part of the English tradition, the commedia dell' arte was a remarkable art form, in that the script was improvised, and actors took on a single stylized role for their acting lives.
The commedia began in Italy in the fifteenth century, and lasted until the eighteenth. Shakespeare refers to the commedia in Jaques' "seven ages of man" speech; touring companies visited England several times during his life.
The characters
The stock characters, wearing masks to exaggerate the characteristics of their roles, of the Commedia must have produced something like the "comedy of humours" developed by Ben Jonson.
There was the Pantalone, the old man, meddlesome and fussy, often a cheated father like the senex of Roman Comedy (compare Polonius).
Pulchinella survives still as Punch, cunning, violent, and always a winner. The fantastic Harlequin, or Arlecchina survives too in pantomime.
There were also serious characters: the Inamorata, the young heroine, in love of course, attended by her servant Columbina (who is far from serious), and her lover the Inamorato.