[1] Between March and June 1829, the Neapolitan government put forward his candidature to the Greek throne, which fell through by Metternich's opposition.

As his brother had yet to produce children, Charles held a high position at court as heir presumptive to the crown until 1836.

[3] On 12 March 1836, King Ferdinand II of the Two Sicilies, issued a decree upholding the 1829 decision of the brothers' late father, King Francis I of the Two Sicilies, that members of the blood-royal of the kingdom whatever their age were required to obtain the consent of the sovereign to marry, and marriages made without this consent were to be deemed to be null and void.

Defying his brother's will, Charles married morganatically Penelope Smyth on 5 April 1836 in Gretna Green, the first stagecoach stop in Scotland after the border city of Carlisle.

Later, Charles applied for special license from the Archbishop of Canterbury to marry (or remarry) Miss Smyth at St George's, Hanover Square.

[4] The King's Envoy Extraordinary and Minister Plenipotentiary, Count de Ludolf, objected to the grant of the licence and a hearing took place in the Court of Faculties on 4 May 1836.

The Master of the Faculties, Dr John Nicholl, refused to grant the licence on the grounds that the royal succession might be affected by the non-recognition of the marriage in Naples.

[6] The Prince of Capua and Penelope had two children:[citation needed] Ferdinand II never forgave his runaway brother.