Milutin became ill and died on 29 October 1321, and Konstantin was crowned king. Civil war erupted immediately, as Dečanski and his cousin, Stefan Vladislav II, claimed the throne. Konstantin refused to submit to Dečanski, who then invaded Zeta, defeating and killing Konstantin. Dečanski was crowned king on 6 January 1322 by Nicodemus, and his son, Stefan Dušan, was crowned "young king". Dečanski later granted Zeta to Dušan, indicating him as the intended heir. Since April 1326 Dušan appears in written sources as the "young king" and ruler in Zeta and Zahumlje. From that fact and the "Old Serbian genealogies and annals", in recent works, some Serbian historians write that Dusan was 14 years old probably in March, or April 1326, and that he was born in 1312, not around 1308.