Most children fathered by a monogamous monarch

Most children fathered by a monogamous monarch
Who
Prince Hartmann
What
21 people
Where
Liechtenstein
When
1686
The most prolific monogamous royal was Prince Hartmann of Liechenstein (1612-1686), who had 21 children by Countess Elisabeth zu Salm-Reifferscheidt (1623-1688).