after the emergence of regional kingdoms in 887-890, with Arnulf's initial realm in light blue Arnulf took the leading role in the deposition of Charles the Fat. In November 887, a
Diet was meeting at
Tribur. Supported by nobles from eastern parts of the Empire, Arnulf seized the opportunity and deposed the ailing Emperor. In the same time, Arnulf was elected and proclaimed as king. Charles agreed to this involuntary retirement, but not without first chastising his nephew for his treachery and asking for a few royal villas in
Swabia on which to live out his final months, which Arnulf granted him. Chiles died at the very beginning of 888, and since Arnulf was elected king only by the nobles of
East Francia, several questions arose regarding the rule over other regions of the
Carolingian Empire. During the spring of 888, Arnulf was staying at
Regensburg, where he received nobles and envoys of eastern Franks, Alamanns, Bavarians, Thuringians, Saxons, and the neighboring
Slavs, but regions of
West Francia,
Burgundy, and
Italy remained out of his scope, electing their own rulers. During 889, he held Diets at
Forchheim and
Frankfurt, trying to secure acceptance among nobles for his sons
Zwentibold and
Ratold, who were born to him outside of wedlock, and also receiving envoys from Normans and Slavs. In the same year, Arnulf organized an expedition against the
Obotrites, a
Polabian Slavic tribe, but without success, and thus the conflict continued up to 895, when a peace agreement with the Obotrites was reached. Like many rulers of the period, Arnulf was heavily involved in
ecclesiastical disputes. In 895, at the Diet of Tribur, he presided over a dispute between the
episcopal sees of
Bremen,
Hamburg, and
Cologne over jurisdictional authority, which saw
Bremen and Hamburg remain a combined see, independent of the
see of Cologne. Arnulf was more a fighter than a negotiator. In 890, he was successfully battling
Slavs in Pannonia. In early/mid-891,
Vikings invaded
Lotharingia and crushed an East Frankish army at
Maastricht. Terms such as "Vikings", "Danes", "Northmen" and "Norwegians" have been used loosely and interchangeably to describe these invaders. In September 891, Arnulf
repelled the Vikings and essentially ended their attacks on that front. The
Annales Fuldenses report that there were so many dead Northmen that their bodies blocked the run of the river. After this victory, Arnulf built a castle on an island in the
Dijle river.
Interventions in West Francia and Burgundy . Arnulf's policies towards
West Francia and
Burgundy were marked by various challenges. Upon receiving news of deposition and death of emperor Charles, nobles of West Francia were faced with several choices. Since Carolingian prince
Charles was still a child, some magnates gave their initial support to duke
Guy of Spoleto, a relative of the Carolingian dynasty, who came from Italy in order to claim the West Frankish throne, but majority opted for count
Odo of Paris. He was crowned king of West Francia in February 888 in
Compiègne, while Guy was crowned king in
Langres in March 888, trying to gain rule over
Lotharingia, including
Upper Burgundy. Failing to achieve those goals, Guy soon left for Italy, while a group of nobles from Upper Burgundy met at
Saint-Maurice and elected local duke
Rudolph as king of those Burgundian regions. Coronations of Guy and Rudolph were conducted without Arnulf's consent, thus initiating long rivalries, that continued for years, while Odo took different approach, recognizing the superiority of Arnulf's position and formally accepting the suzerainty of Arnulf. In May 889, the queen-dowager
Ermengard of
Provence arrived to the court of Arnulf at
Forchheim, making a submission on behalf of her young son
Louis. In August 890, at the regional
Diet of
Valence, local nobles and bishops from
Lower Burgundy and
Provence elected Louis as king in those regions, with Arnulf's consent. In 893, Arnulf switched his support from Odo to young prince
Charles the Simple after being persuaded by
Fulk, Archbishop of Reims, that it was in his best interests. Arnulf then took advantage of the following fighting between Odo and Charles in 894, harrying some territories of West Francia. At one point, Charles the Simple was forced to flee to Arnulf and ask for his protection. His intervention soon forced
Pope Formosus to get involved, as he was worried that a divided and war-weary West Francia would be easy prey for the Vikings. In 895, Arnulf summoned both Charles and Odo to his residence at
Worms. Charles's advisers convinced him not to go, and he sent a representative in his place. Odo, on the other hand, personally attended, together with a large retinue, bearing many gifts for Arnulf. Angered by the non-appearance of Charles, he welcomed Odo at the Diet of Worms in May 895 and again supported Odo's claim to the throne of West Francia. At the same assembly he crowned his illegitimate son Zwentibold as the king of
Lotharingia, including Upper Burgundy, but the Burgundian possessions were out their reach, since those lands were ruled by local kings, Rudolph and Louis.
Wars with Moravia As early as 880, Arnulf had designs on
Great Moravia and had the Frankish bishop
Wiching of
Nitra interfere with the missionary activities of the
Eastern Orthodox priest
Methodius, with the aim of preventing any potential for creating an independent Moravian state. Arnulf had formal relations with the ruler of the Moravian Kingdom,
Svatopluk, using them to learn the latter's military and political secrets. Later, these tactics were used to occupy the territory of the Greater Moravian state. Arnulf failed to conquer the whole of Great Moravia in wars of 892, 893, and 899. Yet, he did achieve some successes. In 893 or 894 Great Moravia probably lost a part of its territory—present-day western
Hungary—to him. As a reward, Wiching became Arnulf's chancellor in 892. In 895, the
Duchy of Bohemia broke away from Great Moravia and became Arnulf's vassal state. An accord was reached between him and Duke of Bohemia
Borivoj I. Bohemia was thus freed from the dangers of Frankish invasion. In 897, Arnulf received envoys from
Sorbs, and also from
Bohemians, who were asking again for the royal assistance in their conflicts with the neighboring Moravians. In his attempts to conquer Moravia, in 899 Arnulf reached out to
Magyars who had settled in the
Carpathian Basin, and with their help he imposed a measure of control over Moravia. ==King of Italy and Holy Roman Emperor==