Feeling he was "wasting his time" writing fiction, he joined the Christian Brothers, a Catholic religious congregation founded by Edmund Ignatius Rice to teach the children of the poor.

[2] "When free from his books he was wont to roam through the neighbouring countries, so rich in ruins, which told him of the past glories of his native land.

Inspired by the successful production of Banim's play Damon and Pythias (1821), Griffin moved to London in 1823; he was nineteen years of age.

After an unsuccessful attempt at becoming a playwright, Griffin endured years of poverty in London, managing only to scrape by through writing reviews for periodicals and newspapers.

At the end of two years he obtained steady employment in the publishing house as reader and reviser of manuscripts, and in a short time became a frequent contributor to some of the leading periodicals and magazines.

In 1838, Griffin burnt all of his unpublished manuscripts and joined the Congregation of Christian Brothers, a Catholic religious order which has as its special aim the education of children of the poor.

However, his play Gisippus was produced posthumously at the Drury Lane Theatre on February 23, 1842 by William Macready, and it ran to a second edition in print.

One of Griffin's most famous works is The Collegians, a novel based on a trial that he had reported on, involving the murder of a young Irish Catholic girl (Ellen Hanley) by a Protestant Anglo-Irish man (John Scanlon).