「妻者，齊也，秦晉之匹」，儒家將夫妻視為一體，生且如此，死當祔之。一夫一妻多妾是中國自古以來的傳統，妾不同於妻，故元配亡後多有續娶，位同正嫡。中國禮法保障了元配和繼室的對等地位，因此夫妻合葬除了元配，繼室理應也是合葬對象之一。唐代兩京地區出現了繼室與丈夫、元配合葬一墓室以及繼室單獨葬在丈夫及元配合葬墓旁的兩種埋葬方式。在唐朝法律的定義下，繼室承繼了元配未完成的家庭責任，具備禮聘而來的正妻身分，故不違反一夫一妻的禮法。但從長安與洛陽附近發掘的夫妻三人合葬墓以及文獻、墓誌銘中對於二妻同時祔葬於夫的爭議來看，唐律的中心思想在生者嫁娶時看似風平浪靜，但卻在身後面對諸妻並列日守備受挑戰。夫妻二人或三人合葬是唐代重要的喪葬習俗，關於夫妻合葬的形式及分類已有諸多學者透過墓誌進行細緻的整理與研究，成果豐碩。誠然，墓誌是研究夫妻合葬的重要基礎，卻也是被抽離於考古學脈絡的材料。在部分經考古發掘、保存完好的墓葬中，墓誌記載的埋葬方式時而與實際情況不同，即使這一類墓葬出土的比例遠不及大量孤立的墓誌，卻有助於思考喪葬行為的多樣性與墓誌本身的侷限性。因此，本文擬在前人的基礎上，以唐代兩京地區考古發掘的墓葬、墓誌及文獻，討論繼室合葬在一夫一妻觀念下的邊緣性。

Monogamy constituted the most appropriate ritual in the core of family in Tang Dynasty, whether living or dead. Thus, joint burial for husbands and wives became an important funeral tradition. Yet, beside the first wives, successor wives who had a formal role in marriage also had the legal right to jointly buried with their husbands. According to the law of the Tang, a man could not have two wives at the same time. But successor wives, who enteried the family after the death of the first wife through the same formal wedding procedure, played as important a role in the family as the first wife in both domestic sacrifices to the ancestors and duties to the family. Even in the funeral system, descendants mourned the same term for mothers and step mothers. With the law, successor wives seemed to be equivalent in all aspects with first wives. But through careful analysis of excavations of tombs around Changan and Luoyang, literature and epigraphs, we can see that joint burial of the three was controversial in reality. Whether a husband was buried in a tomb with both wives, and whether the successor wife was buried m a single tomb might come from personal circumstances (Buddhist faith, childlessness, an augury). But it might also come from the ritual relation between monogamy and successor wives in the Tang Dynasty, which is the main point of this article.