Assassination

During a visit to Rome, Prince Valiant and his companions Sir Tristram and Sir Gawain witness the swift and brutal assassination of Emperor Valentinian III.

Art and text: Hal Foster (from installment #193, October 20, 1940).
Source: Prince Valiant (Vol. 2): 1939-1940 – Hal Foster (Fantagraphics Books, 2010).

Aguar of Thule

Prince Valiant's father, King Aguar of Thule (now present day Norway).

Art: Hal Foster and John Cullen Murphy (from installment #2139, October 15, 1978). At this point in Prince Valiant's run, John Cullen Murphy, who had been quietly assisting Hal Foster since 1970, was well into his first decade of drawing the strip over Foster's writing and roughs.
Source: Prince Valiant (Vol. 49): Road to Sorrow's End, comprising pages, or installments, 2168 (August 27, 1978) through 2211 (June 24, 1979). Fantagraphics Books, 2003.

A Nightmare Realm

Art: Gary Gianni (from installment #3653, February 11, 2007).
Text: Mark Schultz.
Source: Prince Valiant: Far from Camelot – Gary Gianni and Mark Schultz (Andrews McMeel Publishing, 2008).

The Ultimate Conqueror

Art and text: Hal Foster (from installment #115, April 23, 1939).
Source: Prince Valiant (Vol. 2): 1939-1940 – Hal Foster (Fantagraphics Books, 2010).