This book constitutes a study of Southeast Asia, discussing the Malay world's long historical connection with the Muslim people including the Rumi-Turks, Hadramīs and the Ottomans. These connections reflect religious, political and legal co-operations. It also discusses the Ottomans' policy of pan-Islamism and the role of Sultan Abdulhamid II in improving ties with the Malay world and their scholars, rulers and heritage, in the fight against Western colonial powers. In seven essays, the contributors to this book discuss the early religious-intellectual network in the region as well as the evolution of the judicial and political systems. The network of Johor-Ottoman and Hadrami Muslim relationships and the role of Sultan Abu Bakar of Johor strengthen bilateral connections. The translation of the Majallah al-Ahkam (Ottoman Legal Codes) into Malay language gave an expansion to develop legal practice of the codes of Islamic law in Shariah courts of the Malay Archipelago. The scholars individually discussed and analyzed the topic that they present of which the Ottoman and Malay legal structures and their developments; Turkish scholars in the archipelago and the first interaction with Islam; judicial developments; Ottoman fiqh education system in madrasas. It's hoped that this humble work would contribute some input to the heritages of Muslim World.