The most common and most likely answer to this crossword clue is the 5 plus 10 letter word GREAT EXHIBITION
I've seen this crossword clue in The Times
G
R
E
A
T
E
X
H
I
B
I
T
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Buddy explains!
The straight part
We know that "What gave rise to Crystal Palace" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what gave rise to crystal palace = great exhibition.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.