In this part of the study, the researcher, Shaif Sharaf Al-Hakimi addresses three disciplines: The general theoretical summary of the study within the objective limits of the study (reasons for migration, situations of migrants, and the reciprocal impacts of migration). The theoretical summary in this part was conducted at the level of each objective limit mentioned above and according to the historical phases of the Yemeni migration phenomenon, which were classified into five phases: Pre-historic migrations (mythical migrations), Ancient historical migrations (hypothetical migrations), Islamic era migrations (actual migrations), Modern migrations, and Contemporary migrations. The researcher also states the methodology and procedures used in the field aspect, which complemented the theoretical aspect of the study. The descriptive, survey, analytical, and statistical methods were used in the field aspect of the study. In the last part, the researcher reviewed the results of the field study.