Complex sentence: After the First World War ended they Arabs were confident that they would gain independance as promised to them byMcMahon, however they soon discovered that Britain and France made a secret deal in 1916 called the Sykes-Picot Agreement.
Split into simpler sentences: After the First World War ended the Arabs were confident that they would gain independence as promised to them by McMahon. However they soon discovered that Britain and France had made a secret deal in 1916 called the Sykes-Picot Agreement.