congratulatory message to the Emperor
A formal written or spoken congratulatory address, historically presented to the Emperor on auspicious occasions. Now largely historical or ceremonial.
A congratulatory address was presented to the Emperor on the occasion of the New Year.
The wording of the congratulatory message was extremely formal.
From 賀 (congratulation) + 表 (expression, document). The term originates from the practice of presenting formal congratulatory documents to the Emperor in the imperial court.