Complex sentence: During June and July 1933, all competing parties were either outlawed or dissolved themselves and subsequently the Law against the founding of new parties of 14 July 1933 legally established the Nazi Party's monopoly.
Split into simpler sentences: During June and July 1933 all competing parties were either outlawed or dissolved themselves. Subsequently, the "Law against the founding of new parties" of 14 July 1933 legally established the Nazi Party's monopoly.