Complex sentence: Sir James Frazer Stirling FRIBA (22 April 1926--25 June 1992) was a British architect, considered to be among the most important and influential architects of the second half of the 20th century.
Split into simpler sentences: Sir James Frazer Stirling FRIBA (22 April 1926--25 June 1992) was a British architect. He is considered to be among the most important and influential architects of the second half of the 20th century.