Hartmann, Count of Württemberg
Hartmann I (1160–1240) was the Count of Württemberg.
Hartmann I and his brother
Frederick II of Swabia as king and emperor, Hartmann and his brother switched their support to Frederick and later supported his eventual successor Henry VII
.
Around 1200, Hartmann married the heiress to the county of Veringen in Upper Swabia, thus acquiring lands including Altshausen, Burg Alt-Veringen and the county of eastern Apphagaues.
This article is translated (poorly) from that on the German Wikipedia