The death of Philip's older brother Henry VI, Holy Roman Emperor, in 1197 meant that the Hohenstaufen rule (which reached as far as the Kingdom of Sicily) collapsed in imperial Italy and created a power vacuum to the north of the Alps.

Both opponents tried in the following years through European and papal support, with the help of money and gifts, through demonstrative public appearances and rituals, to decide the conflict for oneself by raising ranks or by military and diplomatic measures.

Philip was born in or near Pavia in the Imperial Kingdom of Italy as the tenth child and eighth (but fifth and youngest surviving) son of Frederick Barbarossa, King of Germany and Holy Roman Emperor and his second wife Beatrice I, Countess of Burgundy.

[8][9] From April 1189 to July 1193 Philip was provost at the collegiate church of Aachen Cathedral, while his father left Germany for the Third Crusade in 1189, but he drowned in the Göksu (Saleph) River in Anatolia the next year.

While the Emperor was absent, the princes elected his two-year-old son Frederick as King of the Romans in Frankfurt at the end of 1196; with this move, Henry VI wanted to see his succession secured before he prepared for the Crusade of 1197.

In early 1195, Philip accompanied his imperial brother on his journey to Sicily and at Easter 1195 he was made Margrave of Tuscany, receiving the disputed Matildine lands;[11][12] in his retinue in Italy was the Minnesinger Bernger von Horheim.

[18] Philip enjoyed his brother Henry VI's confidence to a very great extent, and appears to have been designated as guardian for the king's minor son, in the event of his early death.

[22] He appears to have desired to protect the interests of his nephew and to quell the disorder which arose on Henry VI's death: On 21 January 1198, Philip issued a charter for the citizens of Speyer, in which he indicated that he was acting in the name of King Frederick; however, he was overtaken by events.

[23][24] Meanwhile, a number of Princes of the Holy Roman Empire hostile to the ruling Hohenstaufen dynasty under the leadership of Prince-Archbishop Adolph of Cologne took the occasion to elect a German anti-king in the person of the Welf Otto of Brunswick, the second surviving son of the former Saxon duke Henry the Lion and a nephew of King Richard I of England.

The hesitant behavior of Philip gave Otto the opportunity to be crowned by the rightful coronator ("Königskröner") Adolph of Cologne on 12 July 1198 at the traditional royal place in Aachen, which had to be captured before against the resistance of loyal Hohenstaufen liensmen.

[34] In the first months of 1199, the Welf party asked for confirmation of the decision and for an invitation from the Pope for Otto IV to be crowned Holy Roman Emperor.

In the Bull Deliberatio domni pape Innocentii super facto imperii de tribus electis, the Pope set out the reasons for and against the suitability of the respective candidates:[37][38] Philip's nephew Frederick II was put aside due to his youth, and Philip himself was in the eyes of the Pope as "the son of a race of persecutors" of the church (genus persecutorum) because his father Frederick Barbarossa had fought against the Papacy for years.

This happened because faithful, relatives and friends were favored by gifts or the transfer of imperial property, or by a marriage policy that was supposed to strengthen partisanship or promote a change of party.

[clarification needed] [40] In the next few years of the controversy for the throne, the acts of representation of power were of immense importance, because in them not only the kingship was on display, but the role of the great in the respective system of rule was revealed.

In 1199, Philip and Irene-Maria celebrated Christmas with tremendous splendor (cum ingenti magnificentia) in Magdeburg —close to Otto's residence in Brunswick—in the presence of the Ascanian Duke Bernard of Saxony and numerous Saxon and Thuringian nobles.

[62] The Duke of Brabant received Maastricht and Duisburg and the Archbishop of Cologne was able to retain his position in the election and ordination of a King and was rewarded with 5,000 marks for sided with Philip.

[95] Rather, a regionalization of itinerary, awarding of charters and visits to the court can be identified, which historian Bernd Schütte interpreted as a “withdrawal of the royal central authority”.

[106] Allegedly the Wittelsbach scion, already known for his unstable character, had fallen into a rage when he learned of the dissolution of his betrothal to Gertrude of Silesia by her father, the Piast Duke Henry I the Bearded, who was apparently informed of Count Otto VIII's cruel tendencies and in an act of concern for his young daughter decided to terminate the marriage agreement.

For Count Otto VIII this behavior was an act of treason and also felt that his social status was threatened; he swore revenge on the German King, whom he blame for both spurned betrothals, culminating in the murder at Bamberg.

After Philip's death, Otto IV quickly prevailed against the remaining Hohenstaufen supporters, was acknowledged as German monarch at an Imperial Diet in Frankfurt in November 1208 and crowned Holy Roman Emperor by Pope Innocent III the next year.

[118] A Landfrieden was established for this purpose and the Imperial ban on Philip's murderer and alleged accomplices, the Andechs brothers Bishop Ekbert of Bamberg and Margrave Henry II of Istria, was imposed.

Philip's murderer Otto VIII of Wittelsbach (now condemned as vogelfrei) was found in March 1209 by Reichsmarschall Henry of Kalden in a granary on the Danube near Regensburg and beheaded.

[120][121] At Christmas 1213 Philip's mortal remains were re-interred in Speyer Cathedral, which was considered a memorial of the Salian-Staufen dynasty and was the most important burial place of the Roman-German kingship.

Despite great physical strength, the Welf lacked all the important virtues of rulership; for Burchard, he was “haughty and stupid, but brave and tall” (superbus et stultus, sed fortis videbatur viribus et statura procerus).

[131] The image of Philip in posterity had a major impact on Walther von der Vogelweide, who referred to him in an honorable short form as "young and brave man".

Two turning points were considered to be decisive for the central authority's loss of power: the first one, was the Road to Canossa by Henry IV in 1077 (where he lost royal influence over the church)[136] and the second one was the double election of 1198.

In Karl Bosl's work “Die Reichsministerialität” from 1950, Philip and Otto IV's government signified “a huge, if not perhaps the decisive, setback that the German monarchy suffered in its last attempt to build a state”.

Eduard Winkelmann's Yearbooks of German History (Jahrbücher der Deutschen Geschichte) under Philip of Swabia and Otto IV (1878) became the standard reference work of later historiography.

"[141] The decisive factor for this judgment was that Philip didn't fight energetically enough for his kingship and, through the alliance with the French king, granted "the Erbfeind" influence over the Holy Roman Empire.

[144] The older image of the selfish princes who only wanted to weaken the kingship was put into perspective by pointing out that the nobility repeatedly tried to settle the throne dispute.