Title: Alexander I of Serbia
Content:  Alexander was born on 14 August 1876 to King Milan and Queen Natalie of Serbia. He belonged to the Obrenović dynasty. In 1889, King Milan unexpectedly abdicated and withdrew to private life, proclaiming Alexander king of Serbia under a regency until he should attain his majority at eighteen years of age. His mother became his regent. His parents were second cousins. In 1893, King Alexander, aged sixteen, arbitrarily proclaimed himself of full age, dismissed the regents and their government, and took the royal authority into his own hands. His action won popular support, as did his appointment of a radical ministry. In May 1894 King Alexander arbitrarily abolished King Milan's liberal constitution of 1888 and restored the conservative one of 1869. His attitude during the Greco-Turkish War (1897) was one of strict neutrality. In 1894 the young King brought his father, Milan, back to Serbia and, in 1898, appointed him commander-in-chief of the Serbian army. During that time, Milan was regarded as the de facto ruler of the country.
Title: Alexander I of Yugoslavia
Content:  in the Kingdom of Serbia known as the May Overthrow in which King Alexander and Queen Draga were murdered and dismembered. The House of Karađorđević thus retook the Serbian throne after forty-five years and Alexander's 58-year-old father became king of Serbia, prompting George's and Alexander's return to Serbia to continue their studies. After Alexander's 15th birthday, King Peter had Alexander enlisted into the Royal Serbian Army as a private with instructions to his officers to only promote his son if he proved worthy. On 25 March 1909, Alexander was suddenly recalled to Belgrade by his father with no explanation offered other than that he had an important announcement for his son.
Title: Alexander I of Serbia
Content:  Alexander I (14 August 1876 – 11 June 1903) reigned as the king of Serbia from 1889 to 1903 when he and his wife, Draga Mašin, were assassinated by a group of Royal Serbian Army officers, led by Captain Dragutin Dimitrijević.
Title: Alexander I of Yugoslavia
Content:  this Alexander bested Colonel Dragutin Dimitrijević "Apis" and in the wake of this Alexander's father, King Peter, agreed to hand over royal powers to his son. Though Colonel Dimitrijević was the mastermind of the 1903 coup that had restored the House of Karađorđević to the Serbian throne, Alexander distrusted him, regarding his attempts to set himself up as a "kingmaker" and to have the Serbian Army be a "state within the state" existing outside of civilian control as a major threat. Additionally, Alexander saw Dimitrijević as an irresponsible intriguer who having betrayed one king might always betray another. In January 1914, the Serbian 
Title: Alexander I of Yugoslavia
Content:  Alexander Karađorđević was born on 16 December 1888 in the Principality of Montenegro as the fourth child (second son) of Peter Karađorđević (son of Prince Alexander of Serbia who thirty years earlier in 1858 was forced to abdicate and surrender power in Serbia to the rival House of Obrenović) and Princess Zorka of Montenegro (eldest daughter of Prince Nicholas of Montenegro). Despite enjoying support from the Russian Empire, at the time of Alexander's birth and early childhood, the House of Karađorđević was in political exile, with family members scattered all over Europe, unable to return to Serbia. Serbia had recently been transformed from a principality into a kingdom under the Obrenovićs, who 
Title: Alexander I of Yugoslavia
Content:  Alexander I ( – 9 October 1934), also known as Alexander the Unifier,  was a prince regent of the Kingdom of Serbia from 1914 and later a king of Yugoslavia from 1921 to 1934 (prior to 1929 the state was known as the Kingdom of Serbs, Croats and Slovenes). He was assassinated by the Bulgarian Vlado Chernozemski, during a 1934 state visit to France.
Title: Alexander I of Yugoslavia
Content:  have betrayed Serb interests. Because of the frequent changes in loyalty in the Royal Serbian Army in the 19th century between the feuding royal families, Alexander was never entirely convinced that the Serb-dominated officer corps of the Royal Yugoslav Army were completely loyal to him, and always had the fear if he was seen to be betraying Serbdom as the last Obrenović king was, he too might be overthrown and killed. On 8 June 1922 he married Princess Maria of Romania, who was a daughter of Ferdinand I of Romania. They had three sons: Crown Prince Peter, and Princes Tomislav and 
Title: Serbia
Content:  death. King Alexander established a dictatorship in 1929 with the aim of establishing the Yugoslav ideology and single Yugoslav nation, changed the name of the country to Yugoslavia and changed the internal divisions from the 33 oblasts to nine new banovinas. The effect of Alexander's dictatorship was to further alienate the non-Serbs living in Yugoslavia from the idea of unity. Alexander was assassinated in Marseille, during an official visit in 1934 by Vlado Chernozemski, member of the IMRO. Alexander was succeeded by his eleven-year-old son Peter II and a regency council was headed by his cousin, Prince Paul. In August 1939 the Cvetković–Maček Agreement established an autonomous Banate of Croatia as a solution to Croatian concerns.
Title: Alexander, Crown Prince of Yugoslavia
Content:  Alexander, Crown Prince of Yugoslavia, also claiming the crowned royal title of Alexander II Karađorđević ( / Aleksandar II Karađorđević; born 17 July 1945), is the head of the House of Karađorđević, the former royal house of the defunct Kingdom of Yugoslavia and its predecessor the Kingdom of Serbia. Alexander is the only child of King Peter II and his wife, Princess Alexandra of Greece and Denmark. He held the position of crown prince in the Democratic Federal Yugoslavia for the first four-and-a-half months of his life, from his birth until the declaration of the Federal People's Republic of Yugoslavia later in 1945. Born and raised in the United Kingdom, he enjoys close relationships with his relatives in the British royal family. His godparents were King George VI of the United Kingdom and his daughter, the then-Princess Elizabeth (now Queen Elizabeth II). Through his father Alexander is a direct descendant of Queen Victoria, through his great-great-grandfather Prince Alfred, Duke of Saxe-Coburg and Gotha, Victoria's second eldest son. Maternally he is also a direct descendant of Queen Victoria, through his great-great-grandmother Victoria, Empress of Germany, Victoria's eldest daughter. Alexander is known for his support of monarchism and his humanitarian work.
Title: Alexander I of Yugoslavia
Content:  himself into preparing his nation's defense. In a letter to King Nicholas of Montenegro, Alexander wrote: "God has willed yet again that the Serbian people should give their lives for Serbs everywhere ... I pray for the support of my dear and wise forefathers". At the outbreak of World War I he was the nominal supreme commander of the Serbian army; true command was in the hands of the Chief of Staff of Supreme Headquarters, a position held by Stepa Stepanović (during the mobilisation), Radomir Putnik (1914–1915), Petar Bojović (1916–1917) and Živojin Mišić (1918). The Serbian army distinguished itself in the battles at 

Question: Who is the father of Alexander I of Serbia?
Answer: Milan I Obrenović.
Milan I Obrenovic, King of Serbia.