Avignon. To secure his acceptance of their marriage and support against the accusations of Andrew's murder, Joanna sold him the city. The Black Death forced the Hungarians to retreat from Naples in August 1348. Louis and Joanna, who had just had their elder daughter, Catherine, immediately returned to the kingdom. From early 1349 onwards, all documents for the kingdom were issued in the names of both husband and wife, and Louis was indisputably in control of military fortresses. On coins issued during their joint reign, Louis' name always preceded Joanna's. Although he was not officially recognised by Clement as king and co-ruler until 1352, it is likely that Neapolitans considered him their monarch from the moment he started acting as such. Louis took advantage of the turmoil caused by yet another Hungarian attack to wrest complete royal authority from his wife. He purged the court of her supporters, and struck down her favourite, Enrico Caracciolo, whom he accused of adultery in April 1349 and very likely had executed. Official reign In 1350, the King of Hungary launched another invasion, forcing Louis and Joanna to flee to Gaeta. Louis narrowly defeated Hungarian forces with Pope Clement's help. The Pope, however, reprimanded Louis for "treating the Queen as a prisoner and servant", and agreed to recognise Louis as king and co-ruler only on the condition that he accepted the fact that he held the crown in Joanna's right. Their younger daughter, Françoise, was born soon thereafter. Louis received Clement's formal recognition as his wife's co-ruler in all her realms on 20 or 23 March 1352, and was crowned king alongside her on Pentecost on 25 or 27 May 1352. Françoise, by then the couple's only surviving child, died on their coronation day. Louis founded the Order of the Knot on the occasion of the coronation, most likely hoping to enhance the tarnished reputation he shared with Joanna. In 1356, they were crowned in Messina as rulers of Sicily, but failed to capture the entire island, which had been seized from the House of Anjou by the House of Barcelona in 1285 and thereafter ruled as a separate kingdom. The death of their supporter, Clement VI, was a blow to Louis and Joanna. His successor, Innocent VI, excommunicated them for failing to pay their annual tribute to the Holy See. The issue was resolved by a visit to Avignon in 1360. Louis' attempt