[3] In 1859, Donon was instrumental in the creation of the Crédit Industriel et Commercial (CIC), which was supported by the politically influential Duke of Morny, as a competitor to the Pereire brothers's Crédit Mobilier on the model of successful British depository banks such as the London and Westminster Bank.
[4]: 8–14 In 1863, feeling a loss of direct control over the CIC, he created the Société des Dépôts et Comptes Courants (SDCC) and became the new institution's chairman.
[1][6] From 1868, Donon was mayor of the village of Lonrai in the Orne department, where in 1863 he had acquired a large, newly built country house.
From the late 1870s, Donon engaged in increasingly reckless risk-taking at the Société des Dépôts et Comptes Courants and withheld the relevant information from his board.
[7] On 22 July 1893, Donon was convicted and sentenced to six months imprisonment, which he served at the La Santé Prison, and a fine of three thousand francs.