A few days later the Emperor awarded Caxias the Order of Pedro I and raised him from marquis to duke, the highest rank of Brazilian nobility, and a unique distinction during Pedro II's 58-year reign. The Emperor also appointed him to the Council of State in October 1870. But none of this prevented Caxias from attacks and accusations—some petty—in the parliament, including having left his post without permission. The embittered duke wrote to his friend Manuel Luís Osório, Marquis of Erval: "When I was young, my friend, I did not know how to explain why the elderly were selfish, but now that I am old, I see that they are like that because of the disappointments and ingratitudes they suffer during their lives. At least this is what happens to me".