On 26 September 1585 in Wolfenbüttel, the twenty-two-year-old Dorothea married the future Duke Henry Julius of Brunswick-Wolfenbüttel (1564–1613), who was one year her junior.

At the time, her mother Anna was seriously ill and Dorothea had felt very badly and cried pitifully when she said farewell.

[1] The marriage would consolidate a Protestant alliance of German princes, led by Count Palatine John Casimir of Simmern, who had married Dorothea's sister Elizabeth in 1570.

Unfortunately, the marriage would be short-lived as Dorothea would die in childbirth aged 23 on 13 February 1587.

By his second wife, Elizabeth of Denmark, Henry had ten more children, one of whom was named Dorothea.