When Archibald Campbell, 10th Earl, 2nd Duke of Argyll
https://en.wikipedia.org/wiki/Archibald_Campbell,_1st_Duke_of_Argyll was born on July 25, 1658, in Argyll and Bute, Scotland, his father, Archibald VI Campbell, 9th Earl of Argyll
https://en.wikipedia.org/wiki/Archibald_Campbell,_9th_Earl_of_Argyll ,was 29 and his mother, Lady Mary Stuart, Countess of Moray, was 29.

He married Elizabeth Tollemache Campbell, Countess Argyll and Lady Lorne on March 12, 1677, in Edinburgh, Midlothian, Scotland. They had 14 children in 62 years. He died on September 25, 1703, in Newcastle Upon Tyne, Northumberland, England, at the age of 45.

Here is how he connects to my brother-in-law’s family: