The Merovingians stand in stark contrast to our image of Queens. These women were not crowned in the sense that we have come to understand. Rather they were Queens because their husbands were Kings. These are the days in which the Salic Law, that played such a role in Shakespeare's Henry V (though historically not much role at all), are formulating.
Brunhild, Queen to Sigibert, was a powerful Queen who after bearing many children may have murdered her husband in hopes to rule through her eldest son, Childerbert. Some sources report this was part of blood feud between Merovingians and Visigothic Kings (as Brunhild was a Goth). The nobles forced her out of the kingddom for suspician in her husband's death.
At this point she married her brother in law's, King Chilperic's first son, Merovich. Chilperic, Merovich's father, was none to amused and ordered Brunhild off. She then joined her son Childerbert's, still in his minority, at the powerful ducal court of Grundovald where she is involved or so the sources say, of many plots against Chilperic. After some time Childerbert rises to the kingship, and with him his mother. After many years of political in fighting in which Brunhild is suspected in having several Bishops murdered (up to eleven or), and the most famous monk of the age Columbanus chased from the Kingdom, Childerbert dies, and she assumes the regency of her grand children, both of whom stand to gain the throne. One dies soon thereafter and Brunhild is confirmed as a very powerful woman, though technically no long Queen. Many murder plots later and after much machinations geared to keep herself in power, the Lords of Neustria have her (upon the death's of her grand children) arrested, stripped naked, tied to camel, paraded around and then torn apart by wild horses.