Complex sentence: Sir Richard Winstedt, who earlier in 1935, supported the existence of Megat Iskandar Shah as a separate person, soon after the Second World War changed his opinion when he became aware of the descriptions from the "Suma Oriental".
Split into simpler sentences: Sir Richard Winstedt initially supported the existence of Megat Iskandar Shah as a separate person in 1935. However, soon after the Second World War, he changed his opinion when he became aware of the descriptions from the "Suma Oriental".