Nobody really knows why. As for who and how, the answer is not entirely certain but much clearer. Conrad of Botenstejn (or Mulhow), a German knight, is believed to be Wenceslas' murderer, killing him with three stabs into the chest as the young king was either taking a walk to get some fresh air or resting in his bed in the afternoon as the royal entourage stopped in Olomouc on their way to Poland.

The contemporary Chronicon aulae regiae (also known as the Zbraslav chronicle) names Conrad as being apprehended after the murder and killed immediately. However it also says that his guilt cannot be known for certain, and that it is not known on whose behalf he might have acted. Other sources such as contemporary Olomouc records also name Conrad as the killer.

As a side note, a slightly later account, the chronicle of Dalimil, provides what is thought to be an embellished version of the German's demise, as his hand is cut off and hungry dogs are loosed upon him to eat him alive. Despite this it also serves to illustrate the common point that the killer was a German knight called Conrad.

Sadly, we have no definitive answer for the more important question here. Nobody really knows why Wenceslas had to die, and several parties have been suspected of being behind the assassination.

The Habsburgs are one, as duke Albert (or Albrecht) had clashed with Wenceslas' father and might have harbored some ambitions for Bohemian holdings. However he had made peace with Wenceslas a short time after the death of the young ruler's father and was otherwise occupied back home, so his involvement is unlikely.

Władysław I, Wenceslas' challenger for the crown of Poland, is another suspect. Mostly thanks to his father, Wenceslas had for a time been the king of Bohemia, Poland and Hungary. After losing the Hungarian crown, he was prepared to hold on to the Polish one, and to this effect he had raised the levies and was in fact on his way to Poland when he was assassinated.

However just like with Albert, even Władysław's guilt is doubtful at best. While Wenceslas' death was highly beneficial to him and his ambitions for Poland, as he would get the crown soon afterwards, there are no records of his having any Bohemian allies capable of orchestrating an assassination in Olomouc, and if anything, an attempt on the king's life in Poland would make more sense.

So that leaves us with Bohemian nobility, perhaps the most likely though still uncertain party to be behind the murder. They were ambitious, not particularly willing to go to war, and out of all the suspects in the best position to assassinate the king. There is also the odd opinion here and there that some noblemen might not have respected a fairly young and not particularly capable king supposedly prone to excesses and debauchery.

Above all, however, the assassination meant that they would have a say in selecting the new king since Wenceslas was the last of the Premyslid dynasty. As the potential rulers would try to get their support, the local nobles would profit greatly.