Sheba, or Saba, was an ancient South Arabian kingdom that existed in Yemen before 275 BCE. It likely began to exist between c. 1000 BCE and c. 800 BCE. Its inhabitants were the Sabaeans, who, as a people, were indissociable from the kingdom itself for much of the 1st millennium BCE. Modern historians agree that the heartland of the Sabaean civilization was located in the region around Marib and Sirwah. In some periods, they expanded to much of modern Yemen and even parts of the Horn of Africa, particularly Eritrea and Ethiopia. The kingdom's native language was Sabaic, which was a variety of Old South Arabian.
Among South Arabians and Abyssinians, Sheba's name carried prestige, as it was widely considered to be the birthplace of South Arabian civilization as a whole. The first Sabaean kingdom lasted from the 8th century BCE to the 1st century BCE: this kingdom can be divided into the "mukarrib" period, where it reigned supreme over all of South Arabia; and the "kingly" period, a long period of decline to the neighbouring kingdoms of Ma'in, Hadhramaut, and Qataban, ultimately ending when a newer neighbour, Himyar, annexed them. Sheba was originally confined to the region of Marib (its capital city) and its surroundings. At its height, it encompassed much of the southwestern parts of the Arabian Peninsula before eventually declining to the regions of Marib. However, it re-emerged from the 1st to 3rd centuries CE. During this time, a secondary capital was founded at Sanaa, which is also the capital city of modern Yemen. Around 275 CE, the Sabaean civilization came to a permanent end in the aftermath of another Himyarite annexation.