Question: The father of Otto III was Holy Roman Emperor until his death in what year?

Context paragraphs:
Karl Anselm, 4th Prince of Thurn and Taxis: Karl Anselm, 4th Prince of Thurn and Taxis, full German name: "Karl Anselm Fürst von Thurn und Taxis" (2 June 1733, Frankfurt am Main, Free Imperial City of Frankfurt, Holy Roman Empire – 13 November 1805, Winzer bei Regensburg, Electorate of Bavaria, Holy Roman Empire) was the fourth Prince of Thurn and Taxis, Postmaster General of the Imperial Reichspost, and Head of the Princely House of Thurn and Taxis from 17 March 1773 until his death on 13 November 1805.  Karl Anselm served as "Prinzipalkommissar" at the Perpetual Imperial Diet in Regensburg for Joseph II, Holy Roman Emperor and Francis II, Holy Roman Emperor from 1773 to 1797.

Leopold I, Holy Roman Emperor: Leopold I (name in full: "Leopold Ignaz Joseph Balthasar Felician"; Hungarian: "I. Lipót" ; 9 June 1640 – 5 May 1705) was Holy Roman Emperor, King of Hungary, Croatia, and Bohemia.  The second son of Ferdinand III, Holy Roman Emperor, by his first wife, Maria Anna of Spain, Leopold became heir apparent in 1654 by the death of his elder brother Ferdinand IV.  Elected in 1658, Leopold ruled the Holy Roman Empire until his death in 1705.

Henry II, Holy Roman Emperor: Henry II (German: "Heinrich II" ; Italian: "Enrico II" ) (6 May 973 – 13 July 1024), also known as Saint Henry, Obl.  S. B., was Holy Roman Emperor ("Romanorum Imperator") from 1014 until his death in 1024 and the last member of the Ottonian dynasty of Emperors as he had no children.  The Duke of Bavaria from 995, Henry became King of Germany ("Rex Romanorum") following the sudden death of his second cousin, Emperor Otto III in 1002, was crowned King of Italy ("Rex Italiae") in 1004, and was crowned by the Pope as Emperor in 1014.

List of Holy Roman Empresses: Holy Roman Empress or Empress of the Holy Roman Empire is the title given to the consort (wife) or regent of the Holy Roman Emperor.  The elective dignity of Holy Roman Emperor was restricted to males only, therefore there was never a Holy Roman Empress regnant, though women such as Theophanu or Maria Theresa of Austria, who controlled the power of rule, served as de facto Empresses regnant.

Otto III, Holy Roman Emperor: Otto III (June/July 980 – 23 January 1002) was Holy Roman Emperor from 996 until his early death in 1002.  A member of the Ottonian dynasty, Otto III was the only son of the Emperor Otto II and his wife Theophanu.

Otto II, Holy Roman Emperor: Otto II (955 – December 7, 983), called the Red ("Rufus"), was Holy Roman Emperor from 973 until his death in 983.  A member of the Ottonian dynasty, Otto II was the youngest and sole surviving son of Otto the Great and Adelaide of Italy.

Prayerbook of Otto III: The Prayerbook of Otto III or Pommersfelden Prayerbook is an Ottonian illuminated manuscript, made up of 44 bound parchment folios.  It was produced around 984 in Mainz for the private use of Otto III, Holy Roman Emperor, commissioned by his mother Theophanu and Archbishop Willigis.  It is the only prayerbook to survive from the Ottonian era and its texts and images set out a monastic model for an ideal sovereign, making it more precisely a mirror of princes.

Phantom time hypothesis: The phantom time hypothesis is a historical conspiracy theory asserted by Heribert Illig.  First published in 1991, the hypothesis proposes a conspiracy by the Holy Roman Emperor Otto III, Pope Sylvester II, and possibly the Byzantine Emperor Constantine VII, to fabricate the Anno Domini dating system retrospectively, so that it placed them at the special year of AD 1000, and to rewrite history to legitimize Otto's claim to the Holy Roman Empire.  Illig believed that this was achieved through the alteration, misrepresentation, and forgery of documentary and physical evidence.  According to this scenario, the entire Carolingian period, including the figure of Charlemagne, is a fabrication,

Adalbero (archbishop of Reims): Nearing the end of the Carolingian Dynasty, Archbishop Adalbero and Queen Emma led a political party in favor of the Franks allying with the Ottonian dynasty of the Holy Roman Empire in the Frankish courts.  In a series of letters sent to Empress Theophanu, Emma's sister-in-law and consort of the Holy Roman Empire, Adalbero expressed loyalty on behalf of himself, Queen Emma, and her son Louis V ( Adalbero's lord at the time ).  It was Otto I who had named Adalbero Archbishop, along with the other clergy members who were given their positions by the Emperor and is why Adalbero had felt such loyalty towards them.  However, not all clergy felt the same way, and so they created a political party to oppose Queen Emma in the Frankish courts, one whose goal was to reinstate the policies of Lothair I and expand the Frankish kingdom eastward, to gain the territory of Lorraine, Adalbero's home.  The opposing party eventually prevailed when Louis disregarded the advice given to him by the Archbishop and his mother, Queen Emma, which was to seek friendship with Otto III, Theophanu's son.  This unfortunate turn of events forced Adalbero to step down from his position as Archbishop and flee.  This act was perceived as treason by King Louis, and Adalbero was called to trial at an assembly of leading Franks at Compiègne.  The sudden death of Louis V prevented this trial from taking place, and allowed Adalbero to give his support for Hugh Capet as rightful heir and denounce the Carolingian claimant, Charles, Duke of Lower Lorraine.

List of monarchs of Prussia: The monarchs of Prussia were members of the House of Hohenzollern who were the hereditary rulers of the former German state of Prussia from its founding in 1525 as the Duchy of Prussia.  The Duchy had evolved out of the Teutonic Order, a Roman Catholic crusader state and theocracy located along the eastern coast of the Baltic Sea.  The Teutonic Knights were under the leadership of a Grand Master, the last of whom, Albert, converted to Protestantism and secularized the lands, which then became the Duchy of Prussia.  The Duchy was initially a vassal of the Kingdom of Poland, as a result of the terms of the Prussian Homage whereby Albert was granted the Duchy as part of the terms of peace following the Prussian War.  When the main line of Prussian Hohenzollerns died out in 1618, the Duchy passed to a different branch of the family, who also reigned as Electors of Brandenburg in the Holy Roman Empire.  While still nominally two different territories, Prussia under the suzerainty of Poland and Brandenburg under the suzerainty of the Holy Roman Empire, the two states are known together historiographically as Brandenburg-Prussia.  Following the Second Northern War, a series of treaties freed the Duchy of Prussia from any vassalage to any other state, making it a fully sovereign Duchy in its own right.  This complex situation (where the Hohenzollern ruler of the independent Duchy of Prussia was also a subject of the Holy Roman Emperor as Elector of Brandenburg) laid the eventual groundwork for the establishment of the Kingdom of Prussia in 1701.  For diplomatic reasons, the rulers of the state were known as the King in Prussia from 1701 to 1772; largely because they still owed fealty to the Emperor as Electors of Brandenburg, the "King in Prussia" title (as opposed to "King of Prussia") avoided offending the Emperor.  As the Prussian state grew through several wars and diplomatic moves throughout the 18th century, it became apparent that Prussia had become a Great Power that did not need to submit meekly to the Holy Roman Empire.  By 1772, the pretense was dropped, and the style "King of Prussia" was adopted.  Thus it remained until 1871, when in the aftermath of the Franco-Prussian War, the King of Prussia Wilhelm I was crowned German Emperor.  From that point forward, though the Kingdom of Prussia retained its status as a constituent state of the German Empire, all remaining Kings of Prussia also served as German Emperor, and that title took precedence.

Supporting paragraphs: Otto III, Holy Roman Emperor Otto II, Holy Roman Emperor
Answer: 983