If you would like to get only the latest record that is related to another record (Entity) here is one method of doing that by using a derived table:
In the example below we have a Company table that is related to Activity table. We are going to pull the latest Activity related to each Company.
SELECT Company.Name, la.Subject, la.Date
FROM Company
LEFT JOIN (
SELECT Company.ID AS [CompanyID], Activity.Date, Activity.Subject AS [Subject]
, ROW_NUMBER() OVER ( PARTITION BY Company.ID ORDER BY Activity.Date DESC) as rnFROM Company
LEFT JOIN Company_Activity ON Company_Activity.Company_ID = Company.ID
LEFT JOIN Activity ON Activity.ID = Company_Activity.Activity_ID
) as la ON la.CompanyID = Company.ID AND la.rn = 1