I remember it well. It shows an ordinary family trying to live as part of a society of Border Reivers, a world where raid and feud were unavoidable parts of daily life. The wars between England and Scotland had destroyed the normal processes of law enforcement. The setting is a particularly tense time, with Elizabeth of England and Mary Queen of Scots in competition. Also the struggle between Protestants and Catholics in both kingdoms. Amidst all this, the Kers of Stilrig are trying to live an ordinary life.
You see the complex methods that the Borderers had evolved to deal with a disorderly society. Blood feuds and how to resolve them. The Kers of Stilrig are invented and ordinary, or rather minor gentry. Their relative Sir Walter Ker, warden of the Middle March is a real historic figure, though little is known of him and most of what's shown in the series is invented.