Richard the Lionheart on his way to Jerusalem —
Photo Credit: By James William Glass (1850) - Public Domain, https://commons.wikimedia.org/w/index.php?curid=9876554

The siege of Constantinople in 1204 — by Palma il Giovane
Photo Credit: By Palma Le Jeune (1544–1620) - Public Domain, https://commons.wikimedia.org/w/index.php?curid=3106413

Arms of Latin Empire —
Photo Credit: By Arms of Robert de Tarente.svg: https://commons.wikimedia.org/w/index.php?curid=89007173

Alexios V Doukas — The 147th imperial portrait in Mutinensis gr. 122
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=111923533

Polish and Lithuanian conflict with Teutonic Prussia, 1377–1434 —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=1613311

Vytautas and Kęstutis imprisoned by Jogaila —
Photo Credit: By Wojciech Gerson - Public Domain, https://commons.wikimedia.org/w/index.php?curid=1196038

Vytautas the Great — 17th-century painting
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=442086

Battle of Grunwald — Bitwa pod Grunwaldem
Photo Credit: By Jan Matejko - Public Domain, https://commons.wikimedia.org/w/index.php?curid=49004656

King Władysław II Jagiełło, detail of the Triptych of Our Lady of Sorrows in the Wawel Cathedral —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=3287972

Union of Krewo — signed in Kreva on 14 August 1385
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=18338485

Wawel Cathedral — Roman Catholic cathedral situated on Wawel Hill in Kraków, Poland. Nearly 1000 years old, it is part of the Wawel Castle Complex and is a national sanctuary which served as the coronation site of Polish monarchs.
Photo Credit: By Jar.ciurus - Own work, CC BY-SA 3.0 pl, https://commons.wikimedia.org/w/index.php?curid=28124451