Brother of Manoel and considered to be the better driver of the two.
This Portuguese (Lusitanian) driver began in motor sport before the 2nd World War. He often drove with his brother, Manuel, in sports cars but results were slow to come. The brothers seldom left Portugal regarding even a trip to Spain like a journey to the ends of the Earth. Nevertheless in 1937 after Casimiro beat Nuvolari and Hasseis in the prestigious International Circuit of Vila Real with a Jaguar SS100. Bugatti asked him to make a sortie into the outside world, so in 1938 he travelled to Brazil to try to beat the South Americans at the GP of Rio de Janeiro. He qualified on the back row of the grid and though he had an uninspiring race, he finished in 5th mainly due to retirements.
The war came and put a temporary halt to Casimiro's racing.
After the war he became more interested in Sport Cars. Giving up the single-seaters, he adapted naturally to sports cars and with his Ferrari 225S, he had a great season in 1952. He finishes 2nd in the GP of Portugal and won the International Circuit of Vila Real as well as the GP of Vila C Conde, all races in his homeland.
The following year (1953) he bought a Ferrari 250MM and made a few overseas trips. After a 2nd at the GP of Portugal, he scored a 5th at the GP of Senegal, 2nd at the 12 Hours of Pescara and at the Coppa d' Oro di Sicilia he won beating the cream over the Italian drivers. At the end of the year he purchased a Ferrari 375MM which he raced in the 12h Casablanca in December retiring after an accident.
In 1954 he raced the 375MM to victory in the Hedemora GP (Sweden) and finished 7th in the Swedish Grand Prix. Then after a number of minor offs and an accident in a race at the Skarpnäck Airfield in 1955, the car was re-bodied by Scaglietti and sold to Tore Bjurström.
From then on he became more self indulgent and turned into a true gentleman driver. Driving only where and when it suited him. He never left his native Portugal again.
He quit racing after qualifying for the Portuguese Grand Prix in 1958. Casimiro had obtained an entry and rented a Maserati 250F. But after being outgunned in early practice by the new breed of GP driver, Casimiro, feeling the weight of his 41 years, decided to retire.
And that was the end of his racing. His brother was an eminent filmmaker and actor, and Casimiro managed the family accounts.