Rundetårn at University of Copenhagen — The Rundetårn (round tower) was used in the 17th century as an observatory by Ole Rømer.
Photo Credit: By Avda - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=27604636

Solar eclipse of August 21, 1560 — Greatest eclipse 12:30:55 UTC
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=16982913

Total Eclipse of the Sun — Geometry of a total solar eclipse (not to scale)
Photo Credit: By Sagredo - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3653837

UCPH Lecture Plan 1537 — The oldest surviving lecture plan from the university is from 1537
Photo Credit: By P. Hansen - Illustreret Dansk Litteraturhistorie, Public Domain, https://commons.wikimedia.org/w/index.php?curid=2909113

UCPH logo — University of Copenhagen
Photo Credit: By MrBprints - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=70690608

Coat of arms of Denmark —
Photo Credit: By Kongeriget Danmark, file made by Galico (talk) - CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10851483

9th Century Abbasid caliphs —
Photo Credit: By Ro4444 - Own work; Public Domain, https://commons.wikimedia.org/w/index.php?curid=16127397

Lady Jane Grey — cropped from the Streatham Portrait
Photo Credit: By anonymous - Public Domain, https://commons.wikimedia.org/w/index.php?curid=2680115

Death of William Rufus — lithograph by Alphonse de Neuville, 1895
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=1098841

William II of England — cropped
Photo Credit: By Matthew Paris - Public Domain, https://commons.wikimedia.org/w/index.php?curid=6231706

Battle of Hastings — King Harold falls at Hastings, killed by an arrow in his eye (according to the traditional version).
Photo Credit: By Unknown - M. B. Synge: Great Englishmen, 1911. Public Domain, https://commons.wikimedia.org/w/index.php?curid=9471286