At some point, the Melayu Kingdom took its name from the "Sungai Melayu". 'Melayu' then became associated with Srivijaya, and remained associated with various parts of Sumatra, especially Palembang, where the founder of the Malacca Sultanate is thought to have come from. It is only thought to have developed into an ethnonym as Malacca became a regional power in the 15th century. Islamisation established an ethnoreligious identity in Malacca, with the term 'Melayu' beginning to appear as interchangeable with 'Melakans'. It may have specifically referred to local Malays speakers thought loyal to the Malaccan Sultan. The initial Portuguese use of "Malayos" reflected this, referring only to the ruling people of Malacca. The prominence of traders from Malacca led 'Melayu' to be associated with Muslim traders, and from there became associated with the wider cultural and linguistic group. Malacca and later Johor claimed they were the centre of Malay culture, a position supported by the British which led to the term 'Malay' becoming more usually linked to the Malay peninsula rather than Sumatra.