Complex sentence: The house went into decline at the beginning of the 20th century until 1933 when an agricultural engineer with no experience in leather goods, Franz Schwennicke, took over the company from Edmond Delvaux, the last of the Delvaux family line.
Split into simpler sentences: The house went into a gradual decline at the beginning of the 20th century. In 1933 an agricultural engineer with no experience in leather goods, Franz Schwennicke, took over the company from Edmond Delvaux, the last of the Delvaux family line.