[1] Archduke Rainer was born in Agram (the historic Austrian-German name for what is now the city of Zagreb in Croatia), the fourth child and eldest son of Archduke Leopold Salvator of Austria, Prince of Tuscany and Infanta Blanca of Spain (daughter of Carlos, Duke of Madrid).

[2] He received the names Rainer Karl Leopold Blanka Anton Margarete Beatrix Peter Joseph Raphael Michael Ignaz Stephan.

[3] On 6 April 1922, Rainer and his father were present at the requiem mass celebrated in St. Stephen's Cathedral in Vienna for the soul of the Emperor Charles I of Austria.

[8] They reportedly led a demonstration with cries of "Down with the Republic", and marched to the Austrian Parliament Building demanding that the flag be lowered to half-staff in honour of Austria's former sovereign.915 In 1930 Rainer died in the Wiedner Hospital in Vienna from the effects of blood poisoning; he was 35.

[4] Among those present for the funeral were his parents, Archduke Leopold Salvator and Archduchess Blanca, his father's brother Archduke Franz Salvator of Austria with his sons Hubert and Klemens, his mother's uncle Infante Alfonso Carlos of Spain and his wife Infanta Maria das Neves of Portugal, and Dr. Ignaz Seipel (former Chancellor of Austria).