Parameswara adalah seorang anak raja dari Palembang iaitu jajahan takluk Majapahit yang telah terlibat dalam peperangan merebur takhta kerajaan pada akhir abad ke-14. beliau telah berundur mencari perlindungan ke temasik yang pada masa itu di bawah kuasa Siam. Parameswara telah mebunuh Temagi, wakil Siam di Temasik dan akibatnya beliau telah dipaksa keluar dari Temasik. Parameswara telah berundur ke Muar dan kemudiannya membuka Melaka yang pada masa itu merupakan sebuah penempatan kecil. Sejarah melayu ada menyatakan bahawa Parameswara telah memeluk Islam melalui seorang ulama dari Jeddah pada tahun 1414 dan nama baginda telah ditukar kepada Megat Iskandar Syah. Peristiwa ini bermula pada satu malam apabila baginda telah diajar mengucap kalimah Syahadah. Pada keesokan harinya serombongan pedagang dari Jeddah singgah di Melaka dan mereka iniah yang telah mengislamkan para pembesar Melaka. Semasa pemerintahannya, baginda telah berjaya meletakkan asas kemajuan negara Melaka sebagai pusat perdagangan dan pengembangan agama islam di rantau ini.

Parameswara was the son of a king from Palembang, but ruled in Temasik (now Singapore) . after the death of his father, Parameswara became the next king. His reign in Temasik, however, was cut short by the Siamese, who attacked and drove him out of Temasik. Parameswara fled northward to Muar, and after that to Malacca, where he founded that to Malacca, where he founded the Malacca sultanate. During his reign in Temasik, he was said to be an ignorant ruler who spent his day enjoying, without bothering about the peace and order of his Kingdom. He was easily influenced by news brought by the palace officials and did not investigate any allegations. It was said that he instructed the son of Sang Rajuna tapa to be impaled only through allegations which was not really proven. However when he ruled Malacca, embraced Islam and changed his name to Iskandar Syah, he fared for better. He ruled temasik for 32 years compared to only 11 in Malacca, but much more done during the shorter period in Malacca. After his death, he was succeeded by his son, Muhammad Syah, who was the Raja Muda besar.