Complex sentence: Mr. Greeven was an American businessman who had become a Bahá'í in New York in 1927 and moved to Germany in 1930; the family's move to The Hague in 1937 was due to business restrictions in Germany; the Greevens remained in Holland until 1940.
Split into simpler sentences: Mr. Greeven was an American businessman who had become a Bahá'í in New York in 1927 and moved to Germany in 1930. The family's move to The Hague in 1937 was due to business restrictions in Germany; the Greevens remained in Holland until 1940.