William, Prince of Hohenzollern (German: Wilhelm August Karl Joseph Peter Ferdinand Benedikt Fürst von Hohenzollern) (7 March 1864 – 22 October 1927) was the eldest son of Leopold, Prince of Hohenzollern and Infanta Antónia of Portugal.
William was an older brother of Ferdinand of Romania. His first cousins included (among others) Carlos I of Portugal, Albert I of Belgium, Frederick Augustus III of Saxony, and Princess Maria Josepha of Saxony.
Ferdinand I (Ferdinand Viktor Albert Meinrad; 24 August 1865 – 20 July 1927), nicknamed Întregitorul ("the Unifier"), was King of Romania from 10 October 1914 until his death in 1927. Ferdinand was the second son of Leopold, Prince of Hohenzollern, and Infanta Antónia of Portugal, (daughter of Queen Maria II of Portugal and of Prince Ferdinand of Saxe-Coburg and Gotha-Kohary). His family was part of the Catholic branch of the Prussian royal family Hohenzollern.
In 1886, Ferdinand became heir presumptive to the Romanian throne, following the renunciation of his father (in 1880) and older brother. From the moment he settled in Romania, he continued his military career, gaining a series of honorary commands and being promoted to the rank of corps general. He married in 1893 Princess Marie of Edinburgh, granddaughter of both Queen Victoria and Emperor Alexander II.