Complex sentence: On 23 January 1723 he married his cousin, Countess Eleanor of Nassau-Saarbrücken (1707--1769), daughter of Count Louis Crato of Nassau-Saarbrücken and his wife Countess Philippine Henriette of Hohenlohe-Langenburg (a sister of his father).
Split into simpler sentences: On 23 January 1723, he married his cousin, Countess Eleanor of Nassau-Saarbrücken (1707--1769). She was the daughter of Count Louis Crato of Nassau-Saarbrücken and his wife, Countess Philippine Henriette of Hohenlohe-Langenburg (a sister of his father).