This paper explores the longue durée of Kuwaiti citizenship from 1896 to the contemporary era by weaving together socio-political, imperial, legal and maritime history. While most scholars concentrate on the promulgation of nationality laws in the post-oil era, this paper departs from convention by tracing the historical development of citizenship avant la lettre. In doing so, it sheds light on the ad hoc invention of Kuwaiti citizenship on the sea and in borderlands during the late nineteenth and early twentieth centuries, decades before its formal codification in 1948, 1959 and onwards. Using archival data collected in Kuwait, Qatar, and the United Kingdom, this paper approaches the pragmatics of citizenship by assembling micro-histories of “proto-citizenship,” interrogating how macro-level conflicts over borders, jurisdictions, and territorial sovereignties shaped emergent ideas of nationhood and belonging in the Gulf. It similarly demonstrates how these processes were animated by the quotidian struggles of agents in shops, ships, plantations and ports and reveals how heterogeneous actors –including migrants and merchants, Sheikhs and slaves, shopkeepers and sailors, smugglers and customs officials– conceived of, coopted and contested Kuwaiti citizenship. In the early twentieth century, regularized border control and customs regimes policed maritime trade and detained Kuwaiti nakhudas, Arab sailors, Persian and Baluchi migrants, and African divers suspected of smuggling. As customs interpolated regional sovereignties, British, Iraqi and Persian officials demanded legal clarification of Kuwaiti citizenship for those found to be of “dubious nationality.” To dispute foreign jurisdiction, those detained wrote back to the merchants they worked for, asking the Ruler whether the British could intervene on their behalf. In these extended chains of correspondences, elite and subaltern subjects all had to “verify” and define national belonging in order to affirm or dispute citizenship claims, resorting to genealogical, communal, jurisdictional, and other forms of “evidence” to support their arguments. Examining this evolving language of nationality from the perspective of situated actors, this paper scrutinizes these shifting rubrics of Kuwaiti citizenship. It analyzes the regional phenomena that gave rise to, and the power structures that eventually fixed, nationality and governed its attribution. In examining how diverse subjects enacted and expanded citizenship in daily practice, this paper historicizes the genesis of Kuwaiti nationality and reveals the contingency of this category and its historic malleability. In addition to recognizing the agency of marginal actors, analyzing these iterative exchanges denaturalizes current exclusivist citizenship regimes and revitalizes conceptions of citizenship beyond legal or electoral frameworks.