Ernst I, Duke of Saxe-Coburg and Gotha — Dawe 1818-19
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=18253329

William's proclamation as Emperor — Frederick is standing behind his father, while his brother-in-law, the Grand Duke of Baden leads the cheering.
by Anton von Werner
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=2481294

Frederick III, German Emperor —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=6032415

Kaiser Wilhelm I, 1857 —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=57407206

Frederick William IV of Prussia, 1847 —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=61287979

Frederick William III of Prussia —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=45262202

Frederick William II of Prussia —
Photo Credit: By Anton Graff - Public Domain, https://commons.wikimedia.org/w/index.php?curid=90225617

Prince Augustus William of Prussia —
Photo Credit: By G. v. Bern, German painter, active 1740-1800 - Public Domain, https://commons.wikimedia.org/w/index.php?curid=3383799

Flag of Democratic Republic of the Congo —
Photo Credit:

Henry Morton Stanley meets David Livingstone —
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=30901833

"Dr. Livingstone, I presume?" — an illustration from Stanley's 1872 book How I Found Livingstone
Photo Credit: Public Domain, https://commons.wikimedia.org/w/index.php?curid=1543642