The test manager creates the test strategy. 
It is a company-level document the template
The typical things I would include in a test strategy document are : 
* Types of testing 
* Steps that we need to complete before testing 
* The testing approach, including details like number of users, 
creation of test cases, execution approach, ownership,etc.
* QA timelines
 * Testing process with actors and daily steps. 
* Documents to be prepared with respective formats