本文的寫作要旨，在於透過隋末唐初政治社會格局和地緣戰略因素，闡述當日出身貴冑的李淵和李密如何凝聚建制以外的力量，以衝擊楊隋政權，進而開創基業的事蹟；能否成功運用盜賊和豪傑等建制以外的地方力量，以及克服地緣因素的牽制，乃出身貴冑群雄創業成敗的關鍵因素。李淵任職太原留守的時候，以及進兵關中的整個過程之中，一直很著意招納地方豪傑群盜；李密肇起山東，所倚賴的的武力，亦皆來自山東區域的盜賊和豪傑。可見兩人雖然具有深厚的關隴集團背景，但建立基業的過程之中，並沒有專倚關隴集團力量，而就地取材，乃是累積和加強叛變力量的主要原則。這個現象，反映李淵和李密要打倒關隴集團建立的楊隋政權，便必須能夠有效地掌握建制以外的力量。因此，對建制構成毀滅性衝擊的核心人物雖然來自建制，但麾下部屬，往往由建制以外的力量所組成。當日政治社會，皆由世家大族和貴族菁英主導，階級觀念強固，上下壁壘分明，難以逾越，惟李淵和李密收攬地方力量爲己用時，並沒有流露出階級偏見，這種取向，對於他們號召地方力量支持，自有莫大裨益。當日群雄的出身背景，與他們號召地方力量時所展示的影響力，可以稱得上成正比例。貴冑在結納收編地方力量，具有其階級身份所賦予的特殊優勢，這些優勢，自不會在源自草根階層割據人物的經驗之中找到。李淵由於能夠成功奪取關中地區作爲根據地，而且基本上能夠對於興王之地太原作有效的控制，因此，兵員出處和軍隊的向心力，完全不成問題。相對而言，李密集團的核心成員，皆來自山東豪傑群盜，這些人物在情感上對於東都的重視，對李密形成很大的牽制，這亦是李密不能捨東都而西進的原因。李淵與李密皆擁有堅強實力，但兩人爭奪天下的成敗各異，吾人固然可以找到不少可資論述的原因，而地緣因素對於李密麾下部屬動向的制約，相信仍然是一個值得繼續探討的歷史課題。

This paper, focusing on the sociopolitical framework and geo-strategic factor, aims to explain how Li Yuan and Li Mi who were members of the Guanlong clique had made use of the forces alienated by the Sui to strike a severe blow to the establishments. The ability to capitalize on the forces not affiliated to the establishments, namely local bandits and leaders, and overcome the geo-strategic restrictions was essential to the founding of a regime. Li Yuan, during his time in governing Taiyuan and later leading his army to march towards Changan, had managed to recruit local bandits and leaders, while Li Mi, who established his power in the region of Shandong, had also done the same thing. The way adopted by these two historical figures highlights the point that despite their deep connection with the Guanlong clique, the policy of drawing on local human resources rather than relying on the military strength of the Guanlong region was what they had adopted in the process of establishing their own authority. The medieval society of China was dominated by aristocratic elites emphasizing class differentiation, but Li Yuan and Li Mi did not show class prejudice when recruiting the locals from humble origin. No doubt this practice was instrumental in drawing local supports. Li Yuan was able to have the source of military strength well secured as the areas of Guanzhong and Taiyuan had been under his firm control. Contrarily Li Mi was subject to geo-strategic restrictions over time as the majority of his subordinates were from Shandong; this geographical background might explain why Li Mi was unable to make any significant progress in acquiring strategic strongholds located west of Luoyang as his subordinates had listed the capture of this city as a top priority in their military plan. The impact of geo-strategy manifested in the cases of Li Yuan and Li Mi is thus remarkable.