I am Businessman from Lahore Pakistan.. Question is: I am going to apply business visa for Germany. I got a refusal for a UK tourism visa from British High Commission before 4 months ago. Now I have to tell them about my refusal or submit refusal letter with the documents to apply visa in German embassy?

I am a businessman from Lahore, Pakistan. I am going to apply for a business visa for Germany. I got a refusal for a UK tourism visa from the British High Commission 4 months ago. Now do I have to tell them about my refusal or submit the refusal letter with the documents to apply for a visa at the German embassy?