Complex sentence: The Catholic Defence Association was an organisation founded in 1851 by William Keogh, John Sadleir and George Henry Moore to defend the rights of Irish Roman Catholics and of tenant farmers in the country.
Split into simpler sentences: The Catholic Defence Association was an organisation founded in 1851 by William Keogh, John Sadleir and George Henry Moore. The aim of the organisation was to defend the rights of Irish Roman Catholics and of tenant farmers in the country.