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.

Let me give you an example: Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lô during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Link Information: Operation Market Garden was a failed World War II military operation fought in the Netherlands from 17 to 25 September 1944. Answer: from 17 to 25 September 1944
The answer to this example can be: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin?
Here is why: The passage describes the 704th's actions during Operation Market Garden, and the answer specifies when the operation happened.

OK. solve this:
Passage: At the beginning of the 13th century, a Prussian trade route developed that crossed over an isthmus between two large lakes, the Sicieńskie lake and the Zamkowe ("Castle lake"). A defensive wall was built at this spot, and later, a settlement was constructed there as well. The place is mentioned in a twelfth-century document regarding a battle in which Henry of Sandomierz was killed. Under the name "Wambresia" the town was mentioned in a 1251 Prussian Document issued at Chełmża. Bishop Heidenreich of Bishopric of Chełmno received the Chełmno Land from the pope. The Polish duke Konrad I of Masovia turned possession of the settlement over to the bishop of Chełmno. This created a problem because the Teutonic Knights were in control of the Chełmno Land, and a dispute began between the Bishop of Chełmno and the Knights. The Pope at the time, Innocent IV, was not keen to continue the dispute and installed the Bishop as the rightful ruler of the settlement. This disagreement was the first historical mention of the settlement. In 1251, a large church, St. Simon and Judah, was built in the city.
 Link Information: none Answer: none
Answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
How long did the Teutonic Knights control the Chelmno Land?