Simplify the following text for a Grade 14 native English-speaking person.
Original: The epithet `` German war criminal '' and Livingstone 's subsequent jibes refer to the Standard 's owners , the Daily Mail and General Trust , which endorsed Oswald Mosley 's Fascists in 1934 and supported Nazism until 1939 .
Simplified: The epithet `` German war criminal '' and Livingstone 's subsequent jibes refer to the Standard 's then owners , the Daily Mail and General Trust , which endorsed Oswald Mosley 's British Union of Fascists in 1934 .