Born in Poznań on the 22^nd of November, 1879, into a family of intellectuals. He studied law and economy at the universities of Berlin, Munich, Wrocław, Paris, and Strasbourg. At the latter academy he obtained the degree of Doctor of Laws in 1902. In 1905, he passed the exam to be an associate-judge in Wrocław and then served his apprenticeship at courts in Wrocław and Berlin. In 1912 he became assistant professor and the head of the Department of Legal and Political Sciences and of Philosophy of Law at Jan Kazimierz University of Lviv. In 1916 Cybichowski was appointed a professor of the University of Warsaw. From 1919 he was the secretary and chief reporter of the Questionnaire for the Assessment of Constitution Drafts. In 1919-1922 he was a dean of the Faculty of Law at the University of Warsaw. In 1923 he became a judge of the Permanent Court of Arbitration at the Hague; in 1926-1931, he was a judge of the Competence Tribunal of the World Congress of International Law Association in Warsaw. In 1930, the Columbia University in the City of New York granted Cybichowski an honorary doctorate. He died in Poznań on the 30^th of May, 1946. His works include Artikel 76 der Reichsverfassung (1902), Das antike Volkerecht (1907), Międzynarodowe prawo wojenne (1914), O pojęciu i istocie przynależności państwowej (1920), Polskie prawo państwowe (1925, 1927, 1929, and 1933), Encyklopedia podręczna prawa publicznego (1926-1930), Międzynarodowe prawo karne (1927), and Prawo międzynarodowe publiczne i prywatne (1928).