Complex sentence: The First Congress of Rastatt opened in November 1713, between France and Austria, with the negotiations culminated in the Treaty of Rastatt on 7 March 1714, formally ending hostilities and complementing the Treaty of Utrecht, which had been signed the previous year.
Split into simpler sentences: The First Congress of Rastatt opened in November 1713, negotiations were carried on between France and Austria for the purpose of ending the War. The negotiations culminated in the Treaty of Rastatt on 7 March 1714, formally ending hostilities and complementing the Treaty of Utrecht, which had been signed the previous year.