Clan Irvine/Barons of Drum

http://clanirwin.org/files/8514/9192/1739/Copy_of_The_Barons_of_Drum_simplified.pdf - chart showing the lines from William Irvine of Drum (-aft1332) down to David C Irvine, who succeeded his father Charles Francis Irvine of Drum (-1992) and married Caroline Colbeck.

The top half goes like this:

I. William Irvine Baron of Drum 1323 (-aft1332) m Marrote ...

II. Alexander (-aft1381)

III. Alexander (-1410) m ... Montfort

IVA. Sir Alexander (-1411) (Battle of Harlaw) m Elizabeth Keith [but another family site says they were merely betrothed]

IVB. his brother took the name and the wife, dying in 1457

Alexander dvp. betw 1446 and 1452; m ...Abernethy

V. Alexander (-1493) m Marion Forbes

VI. Alexander (-1527) m Janet Keith

VII. Alexander (-1557) m Janet Allardice

Alexander (?) d at Pinkie after marrying Elizabeth Ogilvie and spawning at least four sons: VIII. Alexander (-1602); William; Gilbert; Robert; all but William had male issue and there were cousin marriages very soon

Geni.com has a bit of a jumble between barons III and VI.