The contents of the first Anglo-Japanese Alliance were the following obligations: if either contracting party of the alliance became involved in a war with another country, the other party would maintain neutrality and prevent other countries from joining in the war, and, if either party became involved in a war with two or more countries, the other party would participate in the war to help the ally.
第一次日英同盟における内容は、締結国が他の1国と交戦した場合は同盟国は中立を守り他国の参戦を防止すること、2国以上との交戦となった場合には同盟国は締結国を助けて参戦することを義務づけたものである。