instruction:
In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
question:
Passage: The Panathenaea (, "all-Athenian festival") was the most important festival for Athens and one of the grandest in the entire ancient Greek world. Except for slaves, all inhabitants of the polis could take part in the festival. This holiday of great antiquity is believed to have been the observance of Athena's birthday and honoured the goddess as the city's patron divinity, Athena Polias ('Athena of the city'). A procession assembled before dawn at the Dipylon gate in the northern sector of the city. The procession, led by the Kanephoros, made its way to the Areopagus and in front of the Temple of Athena Nike next to the Propylaea. Only Athenian citizens were allowed to pass through the Propylaea and enter the Acropolis. The procession passed the Parthenon and stopped at the great altar of Athena in front of the Erechtheum. Every four years a newly woven peplos was dedicated to Athena.
 Link Information: is believed to have been the observance of Athena Answer:  Zeus
answer:
Who was the father of the goddess the celebration is believed to have been in honor of?


question:
Passage: Victor (sometimes spelled Viktor) became an officer in the Royal Navy in 1848 and was promoted to Lieutenant in 1854. As a Lieutenant, he served on the first-rate HMS St Jean d'Acre in the Mediterranean under Captain Henry Keppel in 1855; commanded the gunboat HMS Traveller for a few months in 1856 after her launch until she was paid off; served again under Keppel again on the fourth-rate HMS Raleigh in the East Indies and China, until she was wrecked near Macau in 1857. He was recommended for the Victoria Cross for his service in China in 1856. He was promoted to Commander in 1857, and commanded the first-rate sloop HMS Scourge in the Mediterranean. Promoted to Captain in 1859, he took command of the 21-gun corvette HMS Racoon from commissioning in 1863 until 1866, during which time Queen Victoria's second son, Alfred, Duke of Edinburgh (1844–1900) served on board as a lieutenant.
 Link Information: Henry Keppel (14 June 1809 – 17 January 1904 Answer: 46
answer:
How old was Henry Keppel when Prince Victor of Hohenlohe-Langenburg served under him?


question:
Passage: The Polish–Lithuanian–Teutonic War or Great War occurred between 1409 and 1411, pitting the allied Kingdom of Poland and Grand Duchy of Lithuania against the Teutonic Knights. Inspired by the local Samogitian uprising, the war began by Teutonic invasion of Poland in August 1409. As neither side was ready for a full-scale war, Wenceslaus IV of Bohemia brokered a nine-month truce. After the truce expired in June 1410, the military-religious monks were decisively defeated in the Battle of Grunwald (Tannenberg), one of the largest battles in medieval Europe. Most of the Teutonic leadership was killed or taken prisoner. While defeated, the Teutonic Knights withstood the siege on their capital in Marienburg (Malbork) and suffered only minimal territorial losses in the Peace of Thorn (1411). Territorial disputes lasted until the Peace of Melno of 1422. However, the Knights never recovered their former power and the financial burden of war reparations caused internal conflicts and economic decline in their lands. The war shifted the balance of power in Central Europe and marked the rise of the Polish–Lithuanian union as the dominant power in the region.
 Link Information: none Answer: none
answer:

How many days did one of the largest battles in medieval Europe last?