Siege of Capua (1734)

Prelude

The army of Charles of Parma, numbering about 21,000, marched south from Tuscany where it had been assembled, and reached the northern border of Naples on 28 March 1734. Traun had taken most of the Capua garrison, and constructed a fortified line at Mignano, at which he expected conflict with the Spanish forces. However, on 30 March, the Spanish, aided by sympathetic locals, sent 4,000 troops through narrow mountain passes, threatening to flank Traun's position. When Traun learned of this, he ordered a precipitous retreat to Capua, abandoning armaments and camp equipment along the way. The Spanish then proceeded southward toward Naples, bypassing Capua, and entered the city on 10 May after securing the surrender of its fortresses. About 6,000 troops were stationed to blockade Capua cutting off its communications and access to the land for provisions.

While Charles' army was marching south, a Spanish fleet had landed forces on the islands of Ischia and Procida in the Bay of Naples. Austrian garrisons from these islands had been brought to the mainland, where they joined the garrison at Capua (before it was blockaded), raising the size of Traun's garrison to about 6,000. The Austrians were hoping to be relieved by the forces of Florimund Mercy in northern Italy, but these were occupied with the Franco-Sardinian army.

Following the destruction of the Austrian army at Bitonto in May, Spanish forces turned to besiege the three remaining Austrian outposts: Pescara, Gaeta, and Capua. Pescara was the first to surrender, on 29 July, with Gaeta surrendering in August. Charles was then able to detach troops for the conquest of Sicily, and focus the remaining troops on Capua.

Defenses

The fortress of Capua was a substantial construction, although it had not been maintained well in the years immediately preceding this conflict. It had numerous weaknesses, the principle of which were:

• The water supply;
• The poorly-bastioned Naples gate;
• The landscape to the south and west, which was dotted with groves of olive and fruit trees.

The garrison, under the command of Marshal Traun, consisted of 6,000 men, including 10 battalions of infantry from the regiments of Heister, Göldlin, O'Nelly, Carl Lothringen, and Schmettau, 6 grenadier companies, and companies of horseless cuirassiers from the regiments of Pignatelli and Kokoržowa.

Traun may also have benefited from a long-standing friendship with Count Marsillac, the commander of the besieging forces. The two had fought together in previous campaigns, and even shared the same tent on occasion.

Siege

While the Austrians had intended to provision the fort sufficient to keep a garrison of 5,000 for five months, the supplies present in April were only sufficient to keep the garrison for two months. Traun organized a corps of volunteers that engaged in foraging operations during the months of the blockade. Their forays were successful enough that in mid-July the Austrians still had one month's supplies. His prospects for relief, however, were dampened by news that Marshal Mercy had died in the Austrian defeat at Parma and that the Austrians had retreated afterwards.

On 10 August Traun launched an elaborate sortie against the Spanish blockade, which had grown to over 15,000 men. In addition to raiding Spanish supplies, he targeted a boat bridge the Spanish had set up across the Volturno River. Sending several battalions out the Naples and Rome gates in the middle of the night, they spent several hours attempting to reach and destroy the bridge. The Spanish were able to fend off the attacks, but they were only cover for the true operation, in which a picked company of 500 successfully raided the countryside. Around dawn, this force returned with 150 cows, 90 water buffalo, 1,000 sheep. The attempt on the bridge had cost the Austrians over 300 casualties, although they killed more than 350 Spanish and took 52 prisoners (who Traun promptly released).

The siege continued into November, and conditions in the blockaded city became progressively more severe. On 20 November Traun and the Spanish command reached an agreement that Traun would capitulate if relief had not arrived by 30 November. On that day, the Austrian garrison, reduced to about 5,000 men, marched out with the full honors of war, including two field pieces, and boarded Spanish ships to be transported to Triest and Fiume. The only term of the surrender that the Spanish denied was permission for the troops to assist in the northern Italian campaign.