Test strategy comes first ans this is the high level 
document.... and approach for the testing starts from test 
strategy and then based on this the test lead prepares the 
test plan....

Test strategy comes first ans this is the high level 
document.... and approach for the testing starts from test 
strategy and then based on this the test lead prepares the 
test plan....

Test strategy comes first. It is company level 
document.Test plan is a project level document.
I will give some more information about documents

the sequence of deliverables(documents)
1) Test policy-----company level
2)Test strategy-----company level
3)Test methodology----project level
4)Test plan-----project level
5)Test case
6)Test procedure
7)Test case
8)Defect report
9)Final summary report