Complex sentence: From 1887 to 1945, all Governor-General of French Indochina ("Gouverneur-général de l'Indochine Française") made this palace as their residence and office thus this palce in this period was referred to as Governor General Palace.
Split into simpler sentences: From 1887 to 1945, all Governors-General of French Indochina used this palace as their residence and office. The palace in this period was referred to as Governor General Palace.