How to Clear Chat History in Skype for Mac OS X
How to Delete Old Skype Messages
Clear the Chat History of one contact in Skype
3 Ways to Delete Skype History
Just repeat the operations above for other messages that you want to delete.
Not only this, it also keeps users text based chats for maximum 30 days on its cloud server.
Like other similar programs, Skype will keep the chat history for a certain period of time on your device or in the Cloud.
If you are using a recent Android version, you can alternatively search "Skype" on the search bar.
The recorded video calls will be automatically saved as WMV or MP4 files based on your settings.