4th Lord Borthwick William Borthwick
- 1543(
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- 1 4th Lord Borthwick William Borthwick [1] d. 1543
- Margaret Hay
- 2 Master of Borthwick Thomas Borthwick [1.1] d. Between 1528 and 1538
- + Countess of Eglinton Marion Seton b. Bef 1513 d. 30 Sep 1561
- + Countess of Eglinton Marion Seton b. Bef 1513 d. 30 Sep 1561
- 2 Master of Borthwick Thomas Borthwick [1.1]