The Tank Cintrée is among the most architecturally demanding of all Cartier's Tank family. Where the Tank Louis and the Tank Américaine curve gently to follow the wrist, the Cintrée takes the principle to its logical extreme — a case so dramatically arched along its vertical axis that it wraps the wrist with an almost organic fluency. First produced in the 1920s, it represents the Tank at its most jewel-like, a form that prioritises elegance over wearability and is all the more compelling for it. This example was made for Barthelay — the prestigious Parisian watchmaker and retailer whose name graced some of the most refined Cartier pieces of the 1970s, distributed exclusively through their address on the Place Vendôme. Watches produced for Barthelay occupy a specific and closed chapter of Cartier's history: commissions for a house that no longer exists, in quantities that were never large to begin with. The white dial carries the full Cartier vocabulary — Roman numerals, blued steel hands, the cabochon sapphire crown, the railway minute track framing the dial within its characteristic border. In 18k yellow gold, the case develops a warmth that the drama of its curvature only amplifies. The 18k yellow gold deployant buckle visible on the caseback is original to the piece — a detail that confirms this watch has been kept with genuine care across half a century. A Cintrée made for Barthelay is not something that comes to market often.