Sketched in one night in April 1970 and launched as the most expensive steel watch in the world, the octagon here turned fifty and got a gift that lasted twelve months. A rose gold rotor featuring the dedicated 50-years emblem spins behind the sapphire back, and Audemars Piguet retired it the day 2022 ended. Collectors chasing a Royal Oak with a real end date stop looking once they find one.

Presents itself in mint condition with little to no signs of wear. Woven in raised Grande Tapisserie squares, the Bleu Nuit Nuage 50 dial shifts from soft ice blue to deep navy as you move. Ringed by forty brilliant-cut diamonds, the octagonal bezel throws light without ever feeling loud. Carved from solid 18K rose gold, the tapering bracelet alternates brushed tops with mirror-polished edges that flash as your wrist turns.

Functions include hours, minutes, seconds, and date. Everything runs through the screw down crown at three o’clock. Unscrew it counterclockwise, wind about 40 turns, then pull out one click to quick set the date, and one more click to move the hands. Set the hands near 6:30, click back to set the date to yesterday, then pull out again and walk the hands past midnight until today and the right time land together. Screw the crown back down to keep the 50-meter water resistance intact, and the caliber 5900 will hold about 60 hours of power reserve at 4 Hz.

Comes as a complete set, triple-boxed with international warranty card, instruction booklet, document folio, and original hangtag.

Once overlooked, 37mm is now the collector’s ideal size, proportioned for virtually every wrist. Gold and diamonds on a sports watch once felt like too much, until this pairing proved a Royal Oak can go from a boardroom to a black-tie dinner unchanged. True anniversary pieces do not sit still, and where this one goes next is entirely your call.