Half a century ago, Prince Rainier III of Monaco walked the closed-off streets of his capital Monte Carlo. He stopped at the unique Lamborghini Marzal, and chose that as the car he (and his wife Princess Grace) would drive on their lap of honor to open that year’s Monaco Grand Prix.

Now 51 years later, Lamborghini brought the one-of-a-kind concept – now fully restored – back to the Mediterranean principality. And Rainier son’s, the current sovereign Prince Albert II, rode it around those same streets at the start of the Grand Prix de Monaco Historique. Joining His Serene Highness for the historic occasion was his 33-year-old nephew Andrea Casiraghi – Rainier’s eldest grandchild and fourth in the line of succession to the throne. And behind them started a grid of vintage grand prix racers from 1966-72.

The royal run marked the first time that the Marzal has driven in public since 1967. And the momentous occasion was a fitting tribute to a landmark show car. Designed by Bertone with glass gullwing doors, the four-seat GT was the conceptual predecessor of the Espada. Along with the more classically styled Islero, the Espada is now celebrating its 50th anniversary. So Lamborghini Polo Storico – the same department that returned the Marzal concept to its former glory – brought out a similarly restored example of the Espada as well.

Chassis # 9090, the example in question has remained the factory’s property since its construction. It was used for American compliance testing and development back in the day. And it has now had its bodywork, interior, and mechanical and electrical components brought back up to spec. Polo Storico used only original parts in the ten-month process. And glad we are that they did. Because while the Espada may not be one of the most celebrated of Lamborghinis, it may be a classic whose time has come.