Also called Wolof, the Kingdom was formed between the Senegal and Gambia rivers in the 14th century. The King, or Burba Jolof, was beholden to a handful of powerful regional noblemen who acknowledged kinship with the king but developed personal power bases as well. By the early 1500s, the Burba Jolof could field as many as 100,000 infantry and 10,000 cavalry. Fulani and Berber incursions coupled with political weakness eroded away the power of the Burba Jolof. Various Wolof-speaking states established unions with one another, with their heads assuming the powers of Burba Jolof. The 19th century brought with it French colonisation and a conversion to Islam fuelled in large part by anti-European sentiment.