Dovid Hamelech of Prague refers to Rav Dovid Oppenheim who served as the Chief Rabbi of Moravia and later of Prague. Rav Oppenheim amassed one of the largest collections of Jewish books and manuscripts of all time. At the time of his passing his library numbered more than 7,000 printed books and 1,000 manuscripts. His responsa were published under the title Nishal Dovid. He passed away in 1736 and is buried in Prague.