In 1156 Knud V married Helena, daughter of King Sverker I and his first wife Ulvhild; in consequence, Richeza became the step-mother-in-law of her own son. On Christmas Day of that year, Sverker I was murdered by a servant. When Knud V heard about the deed, he went to Sweden in order to console Richeza, but also to bring his half-sister Sophia of Minsk to Denmark to be married to Valdemar, to whom she had been betrothed since 1154. The marriage took place in 1157. On 9 August of that year, King Knud V was killed during a meeting with Valdemar I and Sweyn III. In 1158 Richeza's second son Niels, probably a monk in Esrom Abbey, also died.