Illuminations from 14th and 15th century manuscripts in the collections of the British Library. British Library Catalogue of Illuminated Manuscripts via mesa-medieval.org.

House of the Sun (detail).
House of the Sun (detail). 1444-1445. Made in Rouen, France. Attributed to the Talbot Master. Royal 15 E VI f. 18v. Image © The British Library. Fair use license. via http://www.bl.uk/catalogues/illuminatedmanuscripts/ILLUMIN.ASP?Size=mid&IllID=38834
Trees of the sun, moon and phoenix (detail).
Trees of the sun, moon and phoenix (detail). 1444-1445. Made in Rouen, France. Attributed to the Talbot Master. Royal 15 E VI f. 18v. Image © The British Library. via http://www.bl.uk/catalogues/illuminatedmanuscripts/ILLUMIN.ASP?Size=mid&IllID=38834
Initial-word panel. Shir (song) with a bear and a unicorn, at the beginning of Song of Songs (page detail).
Initial-word panel. Shir (song) with a bear and a unicorn, at the beginning of Song of Songs (page detail). 1300-1325. German. Additional 15282 f. 296v. Image © The British Library. Fair use license. via http://www.bl.uk/catalogues/illuminatedmanuscripts/ILLUMIN.ASP?Size=mid&IllID=52566
Historiated initial 'P'(uer) of the Nativity with a full border with naturalistic flowers including a rose, a columbine, and lilies, at the beginning of the mass of the Nativity.
Historiated initial ‘P'(uer) of the Nativity with a full border with naturalistic flowers including a rose, a columbine, and lilies, at the beginning of the mass of the Nativity. 1475-1525. Made in the Saint Gall region of Switzerland. British Library Harley 294. Image © The British Library. Fair use license. via http://www.bl.uk/catalogues/illuminatedmanuscripts/ILLUMIN.ASP?Size=mid&IllID=24700

Marginalia from the “Chants royaux en l’honneur de la Vierge au Puy d’Amiens.” Collections of the BnF Gallica, the digital library of the Bibliothèque nationale de France.

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Marginalia, “Chants royaux en l’honneur de la Vierge au Puy d’Amiens,” fol. 21r (detail). 1501-1600. Illuminator not known. Collection of the BnF Gallica. Image © BnF Gallica. Fair use license. via https://gallica.bnf.fr/ark:/12148/btv1b8426257z/f47.item.r=du%20Monde
Marginalia, "Chants royaux en l'honneur de la Vierge au Puy d'Amiens," fol. 21r (detail).
Marginalia, “Chants royaux en l’honneur de la Vierge au Puy d’Amiens,” fol. 21r (detail). 1501-1600. Illuminator not known. Collection of the BnF Gallica. Image © BnF Gallica. Fair use license. via https://gallica.bnf.fr/ark:/12148/btv1b8426257z/f47.item.r=du%20Monde
Marginalia, "Chants royaux en l'honneur de la Vierge au Puy d'Amiens," fol. 21r (detail).
Marginalia, “Chants royaux en l’honneur de la Vierge au Puy d’Amiens,” fol. 21r (detail). 1501-1600. Illuminator not known. Collection of the BnF Gallica. Image © BnF Gallica. Fair use license. via https://gallica.bnf.fr/ark:/12148/btv1b8426257z/f47.item.r=du%20Monde
Marginalia, "Chants royaux en l'honneur de la Vierge au Puy d'Amiens," fol. 21r (detail).
Marginalia, “Chants royaux en l’honneur de la Vierge au Puy d’Amiens,” fol. 21r (detail). 1501-1600. Illuminator not known. Collection of the BnF Gallica. Image © BnF Gallica. Fair use license. via https://gallica.bnf.fr/ark:/12148/btv1b8426257z/f47.item.r=du%20Monde

Medieval and fantastic. Paolo Uccello, artist. Living from 1397 to 1475, he mostly painted in Florence when not doing mathematics.

"Tebaide." 1460's.
“Tebaide.” 1460’s. Tempera on canvas. Collection of the Galleria dell’Accademia, Florence. In the public domain in the United States because the artist has been dead over 70 years. via https://commons.wikimedia.org/wiki/File:Paolo_uccello,_tebaide.jpg
"City View of Florence." Undated.
“City View of Florence.” Undated. In the public domain in the United States because the artist has been dead over 70 years. via https://fineartamerica.com/featured/city-view-of-florence-paolo-uccello.html?product=metal-print
"The Hunt in the Forest." ca. 1470.
“The Hunt in the Forest.”ca. 1470. In the public domain in the United States because the artist has been dead over 70 years. via http://davidsartoftheday.blogspot.com/2015/02/paolo-uccello-hunt-in-forest.html

Glorious illuminations from “Sefer Tehillim” which was published in Tehran in 1383. Hebrew with interlinear Persian translation. Maʻṣūmī Tihrānī, ʻAbd al-Ḥamīd, editor. Bahman, Mahdī, calligrapher.

Image 593 (detail).
Image 593 (detail). Collection of the Library of Congress. In the public domain due to age. via https://www.loc.gov/resource/plmp.m118/?sp=593&fbclid=IwAR1Bx5MbS8gKSYOPDbLynsbflxHvQEHSpuU-ngGu5qOkbDbxWtnBtYMDJRE&r=-1.724,
Image 597 (detail).
Image 597 (detail). Collection of the Library of Congress http://www.LOC.gov. In the public domain. via https://www.loc.gov/resource/plmp.m118/?sp=597
Image 518 (detail).
Image 518 (detail). Collection of the Library of Congress http://www.LOC.gov. In the public domain. via https://www.loc.gov/resource/plmp.m118/?sp=518&r=-1.412,0,3.825,1.281,0
Image 598 (detail).
Image 598 (detail). Collection of the Library of Congress http://www.LOC.gov. In the public domain. via https://www.loc.gov/resource/plmp.m118/?sp=598