Complex sentence: S. G. Warburg & Co. was a London-based investment bank founded in 1946 by Siegmund George Warburg, a member of the Warburg family, a prominent German-Jewish banking family; and Henry Grunfeld, a former industrialist in the German steel industry.
Split into simpler sentences: S. G. Warburg & Co. was a London-based investment bank. The Bank founded in 1946 by Siegmund George Warburg, a member of the Warburg family, a prominent German-Jewish banking family; and Henry Grunfeld, a former industrialist in the German steel industry.