The Mateusian Crisis (Portuguese: Crise Mateusiana) was a major government crisis that took place soon after High King Arthur I of Ebenthal's abdication and succession by his brother Mateus I. As soon as he ascended to the throne of Ebenthal, Mateus I passed over the constitution several times, making structural changes without parliamentary approval, ignoring the decisions of the Conclave and the Tribune of Truth, rulling by decree. In conflict with all of the micronation's institutions, he dismissed all the Conclave and Tribune members who spoke against him. With the high King acting illegaly and risking the own existence of the micronation, the houses had no other choice than to ignore his commands. The Conclave and the Tribune acting together in extraordinary session, deposed Mateus and proclaimed him an enemy of the kingdom. As a direct consequence of this, Ebenthal spent almost three years without a monarch, ruled by a regent, until the proclamation of former King Arthur I of Roschfallen as High King of Ebenthal.
From the establishment of Ebenthal, High King Arthur I reigned following strictly the constitutional rules, playing his role with mastery. Constituinal order prevailed and was only disrupted by the First Lord Nilo Moreira's attempt to seize the throne, leading to the Ebenthali Civil War. In late 2018, the High King announced he would have to step down eventually due to his joining the University of Coimbra in Portugal. As soon as he announced his intentions, his younger brother and heir, the then Prince Mateus, Prince of Arturia, start agitations to assume the throne as soon as possible. On occasions where the High King was impossibilitated to take action due to personal matters, Prince Mateus would do, many times, ignoring constitutional rules and being scolded by his brother and other government officials later. As Arthur's travel to Portugal was delayed in six months and he would only join the university on the second half of the year, Mateus' anxiety only grew and talks begun secretly to define if he could be skipped from succession.
In 24 June 2019 Arthur I abdicated as High King of Ebenthal and Prince Mateus automatically succeeded him as Mateus I. He sworn the constitution and soon after dismissed the cabinet, appointing the Count Vinícius of Lahad to be his Grand Vizier and naming Thiago Walker, the Duke of Guanabara, as First Lord of the Conclave. It didn't take long, he started to equip the government with his loyalists.
The conflict begun in early August when Mateus openly promoted that the country should become an absolute monarchy. Despite the denial he received from all other Ebenthali micronationalists, he started act as an autocrat. In 15 August High King Mateus step into the Conclave's matters by issuing two unconstitutional legislative decrees; the first would give him the power to legislate and effectively turn the Conclave into an advisory body, while the second would make of the monarch irresponsible for unconstitutional acts deemed on the good of the nation. The next day the Conclave, advised by the Tribune of Truth, ruled the Royal Decrees null, which was ignored by the High King. On 24 August, the High King once again issued decrees, this time changing the country's political organization into an unitary state, rather than federative. The next day another decree was issued calling for the development of a new constitution, and talks arouse on the potential transformation of the kingdom into an "Ebenthali Empire", with the High King expressing desire not only for the imperial title, but for start an aggressive expansionist policy. His Grand Vizier, the Count of Lahad, declared his cabinet's support to the monarch and comdemned the Conclave's actions, which he called as "deceitful and disrespectful towards the dignity of our King".
On 7 Septermber most of the Legislative Conclave and the all of the Tribune of Truth convened in a joint special session to decide the course of action on how to deal with the monarch and his allies. On the occassion, Nícollas Reis, Duke of Launceston, Lord of the Conclave for Arturia, openly called for the monarch's immediate adbication. Talks continued in three sessions until 18 September. On this last session, Nícollas' brother Pedro Reis, Count of Iustitia and Seneschal of the Tribune of Truth, leading the house in unanimous decision, demanded for the Conclave to give the High King an ultimatum on his abdication. Facing pressure, High King Mateus, advised by most of his cabinet, dismissed the Conclave and the Tribune in 20 September. The dismissal ordered by royal decree was, as ever, ruled illegal and ignored by both houses. On that same day the Minister of War Raphael Sousa, Duke of Sion, successfully turned with the armed forces against the High King and also started demand his abdication, emptying completelly his tier of support. This came as a turning point for the Conclave's leader and originally High King's friend, the Duke of Guanabara, who, in 27 September 2019, along with the Count of Iustitia, as Seneschal, decisivelly passed a cojoint act of law dissolving the cabinet and deposing the High King and rulling him a criminal. The Tribune of Truth declared the "Mr. Mateus Beato Santoro de Sousa, former High King of Ebenthal, has commited the crime of high treason and attempted against the stability of the micronation." and comdemned him to death by hanging which was automatically commuted - as tEbenthal isn't capable to execute the capital penatly - to banishment. Mateus' allies, such as the Grand Vizier Vinícius Lahad, were also sentenced to banishment.
With Mateus' deposition, the House of Beato ceased it's micronational action as far as it is known. Ebenthali government officials numbers drastically decreased as those who supported the deposed monarch suffered with banishment. The Duke of Sion, who had been at the High King's side for most the conflict, was briefly judged by the Tribune of Truth and considered innocent for his decisive action into the Mateus' deposition.
With no monarch, seen as a neutral part, the Conclave offered the Ebenthal crown to be taken by the Duke of Sion, who promptly refused, as he didn't wanted to be as much commited, but proposed himself to rule as Regent while they searched for a new monarch, which was accepted by the parliamentary house. During the following three months, the Ebenthali crown was offered to the former Emperor Petar I of Schneeblutig and the Sultan Omar V of Harran. After both decline, the Count of Iustitia suggested for the government to seek the King Arthur I of Roschfallen, to whom many of them had served before Ebenthal proclaim it's independence from Roschfallen. The Duke of Sion then offered the crown to the Roschfallenian monarch who, disgusted and disappointed by the recent Roschfallenian micronationalism, abdicated that throne and accepted to become the High King Arthur II of Ebenthal.