This study investigates the term, and the poetry of, the Rearguard Poets (saqat al-shuʿaraʾ). It demonstrates through the investigation of both literary and non-literary texts of the Abbasid era that socio-political circumstances were major factors in forming the critical thinking of Abbasid critics as exemplified by al-Asmaʿi. The study argues that the grouping of the rearguard poets (without their consent) indicates that al-Asmaʿi and his fellow critics were interested in the poetry of this group not merely because they found in it the 'purity of the Arabic language' (fasaha) free from linguistic errors or because of the poets' eligibility to be included among the champion poets (fuhūl al-shuʿaraʾ); they were concerned with a much bigger issue: the mission to preserve Arab cultural identity, which those critics felt was being threatened by the changing atmosphere of Abbasid politics, as Chapter One shows. Reverting to the life of the desert and the Bedouin language to create a standard language (ʿArabiyya) marked an important stage in Arabic intellectual life which left its mark on generations of critics and the criteria they used in selecting and judging poetry, as Chapter Two shows. One of the most important features of Bedouin poetry is the predominance of unusual vocabulary (gharib), which served as both a linguistic treasury for philological critics and a foundation for creating a distinctive linguistic identity impregnable to foreigners, as Chapter Three demonstrates. In Chapter Four the norms and values of Bedouin society, which had the tribe at its centre, are analysed using examples of the poetry of the rearguard poets; these are identified with major themes occurring in the poets' panegyrical and satirical poetry. Turning to the inner-self and the persona of the poets themselves in Chapter Five, it becomes clear that although the critics relied on them to provide contemporary examples of Bedouin poetry, the poets for their part were preoccupied by their own interests and were trying to fight for their own causes: for their tribes, for their patrons and for their own concerns as a part of the wider society, which may or may not have intersected with the agendas and concerns of the critical and cultural authorities. Chapter Six examines the stylistic features of the poetry in question, and investigates the influence of Abbasid modern (muhdath) poetry and the refined (badiʿ) style. Examples of Ibn Harma's poetry in particular are thoroughly analysed due to his perceived position as a pioneer poet composing in the new style of the Abbasid era. The study has found that although the creation of the 'rearguard poets' group served the critical authorities' cultural and ideological interests rather than to show the linguistic and artistic value of their poetry, this does not imply that the representation of those poets as providers of good examples of Bedouin poetry in the Abbasid era is invalid. Moreover, the creation of this group was a reaction to the dominance of Persian culture in al-Asmaʿi's time. Furthermore, the poets' language, themes, motifs and imagery served to showcase the interests of early critics and their preferences in poetry despite the lack of compelling evidence that both parties collaborated to promote one unified and clearly stated purpose.