Orson Welles (1915–1985), the celebrated American filmmaker, actor, theatre director, screenwriter, and producer, visited Dublin at the age of 16. Here, he made his professional theatrical debut at the Gate Theatre.
Following his graduation from The Todd School for Boys, Welles left for a tour of Ireland. For a brief (and depressing time), he traveled about the countryside (including a visit to the Aran Islands) on a donkey and spent his time painting “a lost Eden rich in romance and bounteous beauty”. 
Finding himself in Dublin, Welles visited the Gate Theatre, which had been founded three years previously. He fell in love with the atmosphere of the theatre, describing it as a place where “everyone works for the joy of working, the phrase ‘nobody works for money’ being particularly applicable” 
He presented the manager Hilton Edwards with an audacious note that proclaimed:
“Orson Welles, star of the New York Theatre Guild, would consider appearing in one of your productions and hopes you will see him for an appointment.” 
Welles read for the part of the evil Duke Karl Alexander in an adaption of Lion Feuchtwanger’s Jew Suss and did enough to impress Edwards and partner Micheál Mac Liammóir that he got the part. His first night was marred by mishaps but he won a standing ovation in a brilliantly erratic performance.  Mac Liammóir later wrote that Welles’ put on “an astonishing performance, wrong from beginning to end but with all the qualities of fine acting tearing their way through a chaos of inexperience.” 
He had earned his place as a bone-fide member of the company of the rest of the season and later went on to play Cldaius and the Ghost in a production of Hamlet. Apparently, he received some some bad reviews for Cladius but some very good ones for the Ghost.
While in Dublin, Weelers also wrote a ‘Chitchat and Criticism’ column for a weekly paper under the pseudonmyn Knowles Noel Shane.  Anyone know which paper?
Welles was unable to repeat his success in either London or New York and in March 1932, some eight months after leaving, he returned to Chicago.
Between October 1931 and February 1932, a teenage Welles played in five Gate productions; Jew Suss, Hamlet, Death Takes A Holiday, The Dead Ride Fast and Czar Paul. An experience which undoubtedly helped to shape and his professional career.
There you go.
 Charles Higham, The films of Orson Welles (London, 1971), p. 6
 Richard France, Orson Welles on Shakespeare: the W.P.A. and Mercury Theatre playscripts (New York City, 2001), p. 7
 France, Orson Welles, p. 7
 Higham, The films of Orson Welles, p. 6
 Orson Welles and Mark W. Estrin, Orson Welles: interviews
(Mississippi, 2002), p. xxvii
 Michael MacLiammoir, All for Hecuba: an Irish theatrical autobiography (Boston, 1967), p. 129