Complex sentence: Ogilvy was the eldest son of George Ogilvy, 2nd Lord Banff and his second wife, Agnes, the daughter of Sir Alexander Falconer, 1st Lord Falconer of Halkerton.
Split into simpler sentences: Ogilvy was the eldest son of George Ogilvy, 2nd Lord Banff and his second wife, Agnes. She was the daughter of Sir Alexander Falconer, 1st Lord Falconer of Halkerton.