Possible Clues:

• Author from Sicily and I fled valley, falling into Italian river
• Luigi —, Italian playwright
• Luigi -, Italian playwright (Six Characters in Search of an Author)
• Writer getting older - plain ugly
• Be in complete control
• Some of his cast seem to have found him elusive
• Dramatist's country valley edged by Italian river
• In the country, wooded hollow encircled by river writer found
• Writer's work revolving around fugitive's confession — hollow
• Nobel Prize-winning author of Henry IV