Complex sentence: Helped by Allan's spreading influence into allied shipping, railway and banking concerns, the firm was "as good as a bank", known from 1863 as H & A Allan, of Montreal-an intricate part of Allan empire.
Split into simpler sentences: Helped by Allan's spreading influence into allied shipping, railway and banking concerns, the firm was "as good as a bank". From 1863, the company became known as H & A Allan, of Montreal-one segment, but an intricate part of Allan empire.