As king, after an initial conservative period during which he supported various European legitimist movements, he adopted the neo-Guelph idea of a federal Italy, led by the Pope and freed from the House of Habsburg in 1848.

In the meantime, Albertina had moved to Geneva, where Charles Albert joined her from March 1812 to December 1813, and she was married to the Protestant Pastor, Jean-Pierre Etienne Vaucher (1763–1841), a follower of Jean-Jacques Rousseau.

Despite their past, the family was treated well, although Charles Albert had to renounce the title of Count of the Empire, which had been conferred upon him at the military school in Bourges and the annuity which Napoleon had granted him.

Charles Albert travelled to the Grand Duchy of Tuscany and then to Rome on 18 March 1817 and, after a 6-month engagement, married Maria Theresa on 30 September in Florence Cathedral.

In the years following his marriage, however, Charles Albert had extramarital affairs with several women, including Marie Caroline de Bourbon, widow of the Duke of Berry.

But he was also afraid that he would become the object of popular anger if he continued to delay and so, on 13 March 1821, Charles Albert published a proclamation conceding the Spanish Constitution, with the reservation that this grant was pending the approval of the king.

On 15 March, in the presence of the Junta, Charles Albert swore to observe the Spanish Constitution, which had been amended with a few clauses requested by Victor Emmanuel I's queen, Maria Theresa.

[26] On 16 September 1822, the infant Victor Emmanuel barely escaped from a fire in his cot, exposing the tenuous nature of the line of succession, which was taken out of danger by the birth of a second son, Ferdinand, on 15 November.

[36] Despite the conservative attitudes of the period, Charles Albert supported literati who held liberal ideas, such as Carlo Giuseppe Guglielmo Botta, whose books were banned in Piedmont.

[41] The new king was affected by the July Revolution, which had deposed Charles X of France and led to the accession of Louis Philippe, an ex-revolutionary, and as a result, he decided to make an alliance with the Austrian Empire.

[50][51] After the death of king Ferdinand VII of Spain, the nation was divided into two factions: the anti-liberal reactionaries who supported the legitimist aspirations of Don Carlos and the constitutionalists who defended Maria Christina's regency on behalf of Isabella II.

[52] Similarly, in the Portuguese Liberal Wars (1828–1834), which followed the death of John VI, Charles Albert sided with the absolutists under Dom Miguel, who spent time in Piedmont.

[52] At the time of Charles Albert's ascent to the throne in 1831, there were riots in Rome, the carbonari revolt of Ciro Menotti in Modena, and an insurrection in Bologna and Parma which led to the flight of Francis IV and Marie Louise.

Charles Albert, who considered Mazzini's association the "most terrible and bloody", ordered the investigation to continue until it got to the bottom of the matter, acting in accordance with the law but with the utmost severity.

[49] In 1840 the Oriental Crisis, which placed Louis Philippe's France in conflict with the other European great powers, inspired Charles Albert to begin thinking about a program of territorial expansion in the Po valley.

To Massimo d'Azeglio, who had gone to report on the events, Charles Albert said, "that on the day of conflict with Austria, he would throw himself in with his sons, with his army, with all his substance, to fight for the independence of Italy.

"[58] On 8 June 1846, on the orders of Chancellor Metternich, the Austrian ambassador to Turin, Karl Ferdinand von Buol, asked Charles Albert to clarify his position on whether he was with Austria or with the revolutionaries.

A clear message from Turin was delivered by the Milanese liberal, Francesco Arese Lucini [it] on 19/20 March: You may be assured, sirs, that I am giving every possible provision: that I burn with desire to bring to your aid all that is in my power and that I will grasp even the smallest pretext that presents itself.

[69] On 23 March 1848, the Piedmontese embassy to Milan returned to Turin with news that the Austrians had been forced to evacuate the city and that a provisional government headed by Gabrio Casati had been established, which asked Charles Albert to become an ally.

His reactionary past forgotten, the king appeared on the balcony of the royal palace, flanked by the Milanese representatives, waving the tricolour, while the people applauded and shouted, "Long live Italy!

On 21 May, the contingent of 14,000 men from the Neapolitan army which were en route to fight against the Austrians, were ordered by Ferdinand II to return home in light of Pius IX's decision.

The Austrians conquered Vicenza on 10 June, dispersing the Papal volunteers and finally obtained a decisive victory over the Piedmontese in the Battle of Custoza, which lasted from the 22 to 27 July.

[76] On the evening of 27 July 1848, the Austrians agreed to grant a truce if the Piedmontese withdrew to the west bank of the Adda (a little more than 20 km east of Milan), surrendered all the fortresses, including Peschiera and yielded the Duchies of Parma and Modena, whose rulers had been forced into exile.

At the river Adda, some manoeuvres taken by a general on his own initiative left a division isolated and made it necessary to withdraw again, in order to retreat inside the walls of Milan.

Charles Albert went to the Palazzo Greppi [it], ignoring the Milanese desire to resist, he negotiated the surrender of the city to the Austrians in exchange for permitting the safe withdrawal of the army to Piedmont.

According to the noblewoman Cristina Trivulzio di Belgiojoso, who participated actively in the riots in Milan: A contingent of the national guard went up to interrogate Charles Albert on the reason for the surrender.

He turned them away, but was forced despite himself to follow some deputies onto the balcony, from which he spoke to the people, apologizing for his ignorance of the true feelings of the Milanese, saying that he was delighted that they came to the defence so quickly, and solemnly promising to strive for them with his last drop of blood.

Chrzanowski made some significant tactical errors and despite the bravery of the Piedmontese and Charles Albert himself, who fought along with his son Ferdinand in the front lines, the Battle of Novara proved a disastrous defeat.

"[85] Charles Albert's eldest son became king of Sardinia as Victor Emmanuel II and agreed to an armistice with Radetzky on 24 March 1849 at Vignale, effectively obtaining more favourable terms than previously offered.

[96]In 1817, Charles Albert married his second cousin once removed, Maria Theresa of Austria, the youngest daughter of Ferdinand III, Grand Duke of Tuscany, and Princess Luisa of Naples and Sicily.