Question: Aleksander Chodkiewicz, was a noble from the Grand Duchy of Lithuania, founder of the Supraśl Orthodox Monastery, via his mother Jawnuta (Agnieszka) of the Belsky family, he was second cousin to which member of the Jagiellon dynasty, reigned as King of Poland and also as the Grand Duke of Lithuania from 1506 until 1548?
Context: Helena Ivanovna of Moscow (Russian: Елена Ивановна ; Lithuanian: "Elena" ; Polish: "Helena Moskiewska" ; 19 May 1476 – 20 January 1513) was daughter of Ivan III the Great, Grand Prince of Moscow, and an uncrowned Grand Duchess of Lithuania and Queen of Poland as she would not convert from Eastern Orthodoxy to Catholicism.  Her childless marriage to Grand Duke of Lithuania and later King of Poland Alexander Jagiellon was a constant source of tension between the Grand Duchy of Moscow and the Grand Duchy of Lithuania.  Instead of guaranteeing peace, Helena's marriage gave her father Ivan III an excuse to interfere in Lithuanian affairs accusing Alexander of mistreating Helena and repressing Orthodox believers.  This became the pretext to renew the Muscovite–Lithuanian War in 1500.  The war ended with a six-year truce in 1503; the Grand Duchy of Lithuania lost about a third of its territory.  Despite political tensions and religious differences, the marriage was a loving one and the royal couple was close.  After her husband's death in 1506, Helena wanted to return to Moscow but was not allowed.  When she planned to run away, she was arrested and reportedly poisoned. Hieronim Chodkiewicz (Lithuanian: "Jeronimas Chodkevičius" ; ca. 1515–1561) was a noble from the Grand Duchy of Lithuania, who was Elder of Samogitia from 1545 until his death.  He was son of Aleksander and brother of Hrehory and Yurii Chodkiewiczs. Due to the political success of Chodkiewicz and his brothers, the Chodkiewicz family became the second wealthiest family in the Grand Duchy after the Radziwiłłs according to a military census of 1567 – a significant increase from the 1528 census when their father Alexander was 11th on the list.  Chodkiewicz distanced himself from his Eastern Orthodox roots—he possibly converted to Catholicism around 1530 and to Lutheranism around 1550. Alexander I Jagiellon (Polish: "Aleksander Jagiellończyk" ; Lithuanian: "Aleksandras Jogailaitis" ) (5 August 1461 – 19 August 1506) of the House of Jagiellon was the Grand Duke of Lithuania and later also King of Poland.  He was the fourth son of Casimir IV Jagiellon.  He was elected Grand Duke of Lithuania on the death of his father (1492), and King of Poland on the death of his brother John I Albert (1501). Sophia of Halshany or Sonka Olshanskaya (Belarusian: Соф'я Гальшанская, "Sofja Halšanskaja" ; Lithuanian: "Sofija Alšėniškė" ; Polish: "Zofia Holszańska" ;  1405 – September 21, 1461 in Kraków) was a Grand Duchy of Lithuania princess of Halshany.  As the fourth and last wife of Jogaila, King of Poland and Supreme Duke of Lithuania, she was Queen consort of Poland (1422–1434).  As the mother of Władysław III, King of Poland and Hungary, and Casimir IV, Grand Duke of Lithuania and King of Poland, she was the founder of the Jagiellon dynasty. Ivan Chodkiewicz; ( 1420 – 1484) was a noble from the Grand Duchy of Lithuania.  He was a son of Chodko Jurewicz and ancestor of the Chodkiewicz family.  Ivan married Jawnuta (Agnieszka) Belska, first cousin of Casimir IV Jagiellon, King of Poland and Grand Duke of Lithuania.  The marriage into the royal line helped him to obtain positions of starosta of Lutsk (1473) and voivode of Kiev (1480).  During a Tatar invasion in 1482, Ivan and his family were taken hostage.  Ivan died in captivity while his wife, daughter Agrafena, and son Aleksander Chodkiewicz were ransomed and continued the family line. Bona Sforza (2 February 1494 – 19 November 1557) was a member of the powerful House of Sforza, which ruled the Duchy of Milan since 1447.  In 1518, she became the second wife of Sigismund I the Old, the King of Poland and Grand Duke of Lithuania.  Their marriage lasted 30 years until Sigismund's death in 1548.  Ambitious and energetic, Bona became heavily involved in the political life of Poland–Lithuania.  To increase state revenue, she implemented various economic and agricultural reforms, including the far-reaching Wallach Reform in the Grand Duchy of Lithuania.  Her reforms made her the richest landowner in the Grand Duchy.  In foreign policy, she opposed the Habsburgs and sought to secure her eldest daughter Isabella Jagiellon in the Kingdom of Hungary. Michael Glinsky (Lithuanian: "Mykolas Glinskis" , Russian: Mikhail Lvovich Glinsky , Polish: "Michał Gliński" ; 1460s – 24 September 1534) was a noble from the Grand Duchy of Lithuania of distant Tatar extraction who was also a tutor of his nephew, Ivan the Terrible.  As a young man, Glinsky served in the court of Emperor Maximilian I and earned distinction for his military service.  Around 1498 he returned to Lithuania and quickly rose in power and wealth, angering local nobles.  Just after commanding the victorious Battle of Kletsk against the Crimean Khanate in August 1506, he was accused of conspiracy against the deceased Grand Duke Alexander Jagiellon and lost all his wealth.  Glinsky began an armed rebellion against Sigismund I, the new Grand Duke.  The rebellion was unsuccessful and Glinski retreated to the Grand Duchy of Moscow, where he served Vasili III of Russia.  When the Muscovite–Lithuanian Wars renewed in 1512, Glinsky was instrumental in helping Moscow to capture Smolensk, a major trading center.  However, he was not rewarded with the regency of the city.  Angered, he planned to betray Vasili III, but the plot was discovered and he was imprisoned for 12 years.  He was freed after his niece Elena Glinskaya married Vasili III in 1526.  Before his death in 1533, Vasili appointed Elena and Glinski as protectors of his underage sons Ivan and Yuri.  Elena disapproved of Glinsky's influence in the state and had him sent to prison, where he soon died of starvation. Aleksander Chodkiewicz (Lithuanian: "Aleksandras Chodkevičius" , Belarusian: Аляксандар Хадкевіч ; ca. 1475 – 28 May 1549) was a noble from the Grand Duchy of Lithuania, founder of the Supraśl Orthodox Monastery.  He inherited vast possessions from his father Ivan Chodkiewicz, which made him 11th wealthiest person in the Grand Duchy according to the military census of 1528.  Via his mother Jawnuta (Agnieszka) of the Belsky family, he was second cousin to Kings of Poland John I Albert, Alexander Jagiellon, and Sigismund I the Old.  Chodkiewicz quickly gained influence under Alexander Jagiellon, becoming royal marshal.  However, after Alexander's's death in 1506 his career stagnated.  He supported Queen Bona Sforza, gaining her favor and becoming starost of Brest in 1528.  The peak of his career came in 1544 when young Sigismund II Augustus, still influenced by his mother, appointed Chodkiewicz as voivode of Nowogródek and his son Hieronim as castellan of Trakai. Mikhailo Aleksandrovich Olelkovich (executed on August 30, 1481 in Vilnius) was a noble from the Olelkovich family of the Grand Duchy of Lithuania.  He was the brother of Prince Simeon Olelkovich of Kiev and cousin of Grand Prince Ivan III of Moscow.  Mikhailo was allegedly involved both in bringing the Judaizer Heresy to Novgorod and the failed defection of the city to the Grand Duchy of Lithuania in 1471.  He also organized a coup against Casimir IV Jagiellon, King of Poland and Grand Duke of Lithuania, but was discovered and executed in 1481.  Mikhailo's son Semen continued the family line. Sigismund I of Poland (Polish: "Zygmunt I Stary" , Lithuanian: "Žygimantas I Senasis" ; 1 January 1467 – 1 April 1548), of the Jagiellon dynasty, reigned as King of Poland and also as the Grand Duke of Lithuania from 1506 until 1548.  Earlier, Sigismund had been invested as Duke of Silesia.  A successful monarch and a great patron of arts, he established Polish suzerainty over Ducal Prussia (East Prussia) and incorporated the duchy of Mazovia into the Polish state, securing the nation's wealth, culture and power.
Answer: Sigismund I of Poland