Barbe-Nicole is the daughter of a wealthy textile merchant in Reims who grows up in a society transformed by political upheaval. Following her husband's sudden passing, she becomes a 27-year-old widow who assumes control of his fledgling wine brokerage. She possesses a pragmatic understanding of survival and an intense drive to succeed in a male-dominated industry. Her boldness leads her to invent new champagne production methods and risk everything on international expansion.

François is an energetic dreamer from a prosperous textile family. He possesses a deep passion for expanding his father's small wine brokerage into an international enterprise, a vision he shares with his new wife. Though well-educated and enthusiastic, he lacks practical business follow-through and struggles with severe depression, casting a shadow over his commercial efforts.

Louis is a talented, German-born export agent who travels extensively to secure international sales. He works under the constant threat of wartime danger and political suspicion, frequently crossing hostile borders. His linguistic skills and market intelligence make him an indispensable commercial asset, and he shares an audacious strategic vision for the company's future.

Napoléon is the ambitious ruler of France whose military campaigns upend the European economy. His implementation of the Continental System and trade blockades paralyzes European commerce. Though he does not directly target the champagne houses, his policies create immense scarcity and logistical nightmares for merchants attempting to export their goods.

Mathieu-Édouard is a young businessman who rapidly advances through the company ranks. Despite having limited winemaking background initially, he demonstrates strong financial acumen and managerial skill. He provides structural stability to the enterprise during periods of economic stress and helps modernize the company's corporate structure.

Jean-Rémy is the wealthy heir to the Moët champagne house in Épernay. He represents a traditional model of commercial success built on elite patronage and established male networks. His vast resources and prestigious connections make him a formidable rival in the luxury wine industry.

Tilar is an American-Canadian author and cultural historian acting as the guide through the historical archives. She actively pieces together the sparse surviving documents to reconstruct the life of a 19th-century businesswoman. Her academic background allows her to contextualize the era's social restrictions and economic shifts.

Nicolas is a wealthy textile industrialist and Barbe-Nicole's father. He maintains his fortune during the French Revolution through careful political duplicity, publicly joining the radical Jacobin party while secretly holding Catholic and royalist sympathies. He is socially ambitious and eager to secure aristocratic connections for his descendants.

Jeanne-Clémentine is the matriarch of the Ponsardin family. She helps raise her children in an environment of wealth and privilege, maintaining the family's domestic stability during times of intense political upheaval.

Philippe is François's father, a cautious and practical businessman. He doubts the wisdom of international expansion during wartime and maintains tight control over the family's capital. His conservative approach acts as a counterbalance to his son's lofty ambitions.

Clémentine is Barbe-Nicole and François's only child. She is socially anxious and sheltered, spending part of her youth at a convent boarding school in Paris. She becomes the focus of her mother's intense desire to secure an aristocratic lineage for the family.

Louis is the Count of Chevigné, a young nobleman whose family lost its fortune and many of its members during the French Revolution. He possesses a refined aesthetic sense and expensive tastes but lacks the income to support them. He views marriage as a practical avenue to secure financial stability.

Alexandre is a textile merchant and established winemaker in Reims. He brings technical experience and capital to a new venture with the Clicquot family. He serves as a required supervisor for the business, representing the era's patriarchal requirement for male oversight in commerce.

Jean-Antoine is a French chemist and statesman whose research provides the theoretical foundation for industrial winemaking. His work quantifies the role of sugar in fermentation, a process that becomes known as chaptalization. His scientific approach allows merchants to manage production with consistent results.

Antoine is the cellar master who manages the physical production of the champagne. He works directly with the technical challenges of fermentation and sediment removal, implementing highly secretive new methods in the underground cellars.

Louise is an enterprising widow who assumes control of her late husband's wine business. She demonstrates keen strategic focus by investing heavily in the Pommery brand and its infrastructure. She pays close attention to shifting international tastes, particularly in the British market.