Complex sentence: As such he had become known to the Ottoman Interior Ministry authorities and their German technical advisors, travelling over the German-designed, built, and financed railways during the course of his research.
Split into simpler sentences: As such he became known to the Ottoman Interior Ministry authorities and their German technical advisors. Lawrence came into contact with the Ottoman-German technical advisers, travelling over the German-designed,-built, and-financed railways during the course of his research.