He was a third son of Duke Adolf of Holstein-Gottorp and his wife Christine of Hesse-Kassel (or Hesse-Cassel).

He became the Duke after the deaths of his two elder brothers; as Duke of a sovereign state in the early 17th century, he became involved with the religious wars of the time.

[1] After succeeding in 1590 his father as ruling Duke, the Bremian Chapter enforced his resignation in favour of his younger brother John Frederick of Holstein-Gottorp, Prince-Bishop.

John Adolf entered into a secret treaty with his cousin, King Christian IV, to suppress the nobility,[2] in 1608.

[3] He wrote at least one diplomatic letter to Queen Elizabeth I.