Living during a century characterised in Europe by recurring outbreaks of plague and frequently violent political confrontations, his own career was marked by conflict.

[1][2][3][4] Clau Maissen was born into a leading family of the Cadi (Surselva) region at Sumvitg / Somvix, a small town in the mountains west of Chur, along the route to the Oberalp Pass.

Julius Maissen, probably a direct forefather, had been a top local administrator in the mid-sixteenth century: the family and its position were well established, though the twentieth century historiography includes some intense debate over the extent of the family's wealth in the 1620s and 1630s, when Clau Maissen was growing up, and western Europe was embroiled in the hugely destructive Thirty Years' War.

[3][7] Maissen twice served, in addition, as a member of the "Syndikaturkommission", an oversight authority comprising nine men, mandated to provide reports on Veltlin/Valtellina to the Federal Diet/Council of the so-called "Three Leagues" [of the eastern Swiss confederacy] / "Raetia" about Veltlin/Valtellina.

The valley, was important to the Swiss, but was also of continuing strategic importance throughout this period as a vital communication route for the "Spanish party", the term frequently used to identify Swiss supporters of the House of Hapsburg, which was keen to retain influence and access in the valley in order to be able to transit from Spain, via the port of Genoa and Hapsburg-controlled Milan, to Hapsburg territories in and beyond Austria.

In 1655, very shortly after assuming the papacy, Pope Alexander VII had issued a bull separating Disentis Abbey and 14 surrounding parishes from the control of the diocese, becoming instead a quasi-diocese in its own right, directly answerable to the Holy See.

[3] Thanks to the protection both of fellow adherents of the "Spanish" party and of the Bishops of Chur, and especially of the Prince-Bishop Ulrich VI de Mont, Maissen held important political positions in the Cadi/Disentis district, in the so-called "Grey League" (proto-canton) and in its (virtual) free cities, almost without a break between the mid-1640s and the mid-1670s.

[1][3] Maissen's opponents in Cadi (Surselva) included local aristocrats and land owners, political rivals and members of the ant-Hapsburg "French" party.

[9] That the nature of justice locally had changed had become apparent six months earlier when the court had ordered the burning of 28 witches and had one man hanged.

[11] Dean Schgier suspected the Abbot of Disentis and his brother of having together commissioned the murder of Maissen, but evidence sufficient to follow up on these suspicions was lacking.