[2] The background of this treaty was that Christopher I intended his son and heir Philip I to marry Joan, the heiress of Hachberg-Sausenberg.

1485 – died 1543), became Countess of Neuchâtel after her father's death in 1503, while Christopher obtained Sausenberg, Rötteln, Badenweiler and Schopfheim.

Joan and the House of Orléans-Longueville contested the Rötteln treaty and they tried to rally support for their case from the Swiss cantons of Solothurn, Luzern, Fribourg and Bern.

In 1474 and 1475, he participated in the Burgundian sieges of Neuss and Nancy; in 1476 he fought with Charles the Bold in the battles of Grandson and Murten.

After the defeat of Charles the Bold in the 1477 Battle of Nancy, Margrave Philip turned away from Burgundy and sided with France, in an effort to avoid losing his Burgundian possessions.