You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Warsaw

Context:
The first fortified settlements on the site of today's Warsaw were located in Bródno (9th/10th century) and Jazdów (12th/13th century). After Jazdów was raided by nearby clans and dukes, a new similar settlement was established on the site of a small fishing village called Warszowa. The Prince of Płock, Bolesław II of Masovia, established this settlement, the modern-day Warsaw, in about 1300. In the beginning of the 14th century it became one of the seats of the Dukes of Masovia, becoming the official capital of Masovian Duchy in 1413. 14th-century Warsaw's economy rested on mostly crafts and trade. Upon the extinction of the local ducal line, the duchy was reincorporated into the Polish Crown in 1526.

Question:
Who was Boleslaw II of Masovia?

The Prince of Płock