Complex sentence: Robert Blackburn (26 September 1927--16 July 1990) was an Irish educationalist instrumental in establishing the International Baccalaureate Organisation in the 1960s.
Split into simpler sentences: Robert Blackburn (26 September 1927--16 July 1990) was an Irish educationalist. He was instrumental in establishing the International Baccalaureate Organisation in the 1960s.