Year 985 - Golden Seal
Pontus Weman Tell has a theory that the Curmsun Disc is a golden seal ordered by Theophanu to confirm or reinstall Harald on the throne. He uses a philological analysis and shows that the disc most likely is produced before the introduction of the g-rune around year 1000 as Gormson is transliterated as CVRMSVN and not GVRMSVN. Two different transliterations of the word king strengthen his theory. The coin inscriptions of four Hiberno-Norse Kings during the 10th century use the transliterated word CVNVNC for king, see example below:
Raven Penny – Insription CVNVNC
Source: Wikmedia Commons
while the coin inscription of Sihtric around year 1000 uses the transliterated word CVNVNG for king after the introduction of the g-rune.
The use of Old Norse like the word Taner on the Curmsun Disc ends in coin inscriptions in the beginning of the 11th century which furthermore strengthens a manufacturing date before year 1000. As Scania was concurred towards the end of Harald Bluetooth´s life the disc was most likely produced after year 980.
In the middle of the 980s Sweyn Forkbeard rebelled against his father Harald Bluetooth. A decree from empress Theophanu that confirmed or reinstalled Harald on the throne could have been issued as Harald ought to be preferred over Sweyn in the Holy Roman Empire. Theophanu may have ordered bishop Egizo to manufacture the Curmsun Disc with help from her fellow citizens in Jumne.
His article is written under the supervision of Ph.D. Jens Nieling and is published on Academia: https://www.academia.edu/29233334/The_Curmsun_Disc_-_Harald_Bluetooth_s_Golden_Seal.