Complex sentence: At an early age Shlomo Kalo, 12 years old, did join an anti-Fascist underground in Bulgaria when in July 1940 the Bulgarian government had announced its decision to curb the rights of the Jewish minority.
Split into simpler sentences: At an early age Shlomo Kalo, 12 years old, did join an anti-Fascist underground in Bulgaria. As in July 1940 the Bulgarian government had announced its decision to curb the rights of the Jewish minority.