Complex sentence: Frau Johanna (or Hanna) Solf, the widow of Dr. Wilhelm Solf, a former Colonial Minister under Kaiser Wilhelm II and ex-Ambassador to Japan, had long been involved in the anti-Nazi intellectual movement in Berlin.
Split into simpler sentences: Frau Johanna (or Hanna) Solf, the widow of Dr. Wilhelm Solf. Frau Solf had long been involved in the anti-Nazi intellectual movement in Berlin.