James Burnett of Craigmyle was the second son of Alexander Burnett of Leys and Katherine Gordon. When he was 18 years of age he married a cousin, Elizabeth Burnet, daughter of Thomas Burnett of Craigmyle and Tillihaikie.
Alexander and Elizabeth had a number of children, including four sons: 1. Alexander, his successor of Craigmyle, 2. Thomas, who founded the Burnetts of Kemnay, 3. James, who founded the Burnetts of Monboddo and 4. Robert, who became "Tutor of Leys".
Alexander Burnett of Craigmyle was admitted to the Scottish Bar in 1642 and was a Commissioner of War for Kincardineshire. He married Christian Fraser of Strichen, with whom he had five children.
His eldest son, also Alexander, succeeded his father in 1677. In 1682 he was knighted by King Charles II. He married Nicholas Young of Auldbar and produced three daughters. Since there were no direct male heirs, considerable litigation ensued after his death. In the end, everything was decided in favor of his daughters.

This branch of the family is now extinct in the male line.