Here's a short story:

Lublin is the ninth largest city in Poland and the second largest city of Lesser Poland. It is the capital and the center of Lublin Voivodeship ("province") with a population of 349,103 (March 2011). Lublin is the largest Polish city east of the Vistula River, and is located approximately to the southeast of Warsaw by road. 

One of the events that greatly contributed to the city's development was the Polish-Lithuanian Union of Krewo in 1385. Lublin thrived as a centre of trade and commerce due to its strategic location on the route between Vilnius and Kraków; the inhabitants also had the privilege of free trade in the Grand Duchy of Lithuania. The Lublin Parliament session of 1569 led to the creation of a real union between the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania, thus creating the Polish-Lithuanian Commonwealth. Lublin also witnessed the early stages of Reformation in the 16th century. A Calvinist congregation was founded and certain groups of radical Arians also appeared in the city, making it an important global centre of Arianism. At the turn of the centuries, Lublin was also recognized for hosting a number of outstanding poets, writers and historians of the epoch. (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: Which city is the subject of the article?
Guess: Lublin
Confidence: <appropriate level of confidence in this guess>

Question: What country is it in?
Guess: Poland
Confidence: <appropriate level of confidence in this guess>

Question: How big is it, in terms of rankings?
Guess: largest Polish city east of the Vistula River
Confidence: <appropriate level of confidence in this guess>

Question: What city is it near?
Guess: Warsaw
Confidence: <appropriate level of confidence in this guess>

Question: What is it the capital of?
Guess: Lublin Voivodeship
Confidence: <appropriate level of confidence in this guess>

Question: When was that figure collected?
Guess: unknown
Confidence: <appropriate level of confidence in this guess>

Question: On what date, was the population of the city estimated?
Guess: March 2011
Confidence: <appropriate level of confidence in this guess>

Question: What was one event that made a large contribution to its development?
Guess: Polish-Lithuanian Union of Krewo
Confidence: <appropriate level of confidence in this guess>

Question: When did that happen?
Guess: 1385
Confidence: <appropriate level of confidence in this guess>

Question: Did the city do well as a trading hub?
Guess: yes
Confidence: <appropriate level of confidence in this guess>

Question: Why?
Guess: its strategic location
Confidence: <appropriate level of confidence in this guess>

Question: What other advantage did its residents enjoy?
Guess: free trade
Confidence: <appropriate level of confidence in this guess>

Question: What parliamentary event happened there?
Guess: Parliament session of 1569
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: Which countries did that unite?

Crown of the Kingdom and the Grand Duchy