All times Eastern

SUNDAY, JUNE 20

Quest for King Arthur

History Channel, 9 p.m.

Young and old alike in the Western world have loved the legends about the Knights of the Round Table for centuries. Do these tales of chivalry have any basis in fact?

MONDAY, JUNE 21

History Detectives

PBS, 9 p.m.

This investigative series' second season opens with probes of the ironclad submarine that is on display in New Orleans; a pipe said to have belonged to the Sioux leader Red Cloud; and a house in Union, N.J., that inventor Thomas Edison might have designed.

MONDAY, JUNE 21

Liberty! The American Revolution

PBS, 10 p.m.

“The Reluctant Revolutionaries,” the first installment of this sixpart series, deals with the years 1763-1775, when American patriots in each colony banded together to resist British infringements on their God-given rights and liberties. Next Monday's chapter, “Blows Must Decide,” covers the opening of hostilities in 1775 and 1776. Each show includes dramatic readings and interviews with scholars. First broadcast in 1997.

TUESDAY, JUNE 22

Scientific American Frontiers

PBS, 9 p.m.

This episode, “The Dark Side of the Universe,” chronicles discoveries in recent years that suggest most of the universe consists of unseen dark matter and dark energy.

WEDNESDAY, JUNE 23

The Lost Dinosaurs of Egypt

History Channel, 8 p.m.

This show chronicles the recent discovery of a “new” species of dinosaur in Egypt.

WEDNESDAY, JUNE 23

Rebels and Redcoats: How Britain Lost America

PBS, 9 p.m.

Tonight and next Wednesday, this two-part special on America's War of Independence tells the story from the point of view of the losing side, the British and the Loyalists. Tonight's two-hour segment spotlights the Boston Massacre, Lexington and Concord, Washington's crossing the Delaware, the British defeat at Saratoga and France's alliance with America. Next Wednesday's show covers operations in the South, the battle of King's Mountain, the French fleet off Virginia and the surrender at Yorktown in 1781.

THURSDAY, JUNE 24

Guy Pearce's Ultimate Guide to Tigers

Animal Planet, 8 p.m.

The Australia-bred actor tells us what he's learned about tigers.

FRI.-SAT., JUNE 25-26

St. Josemaría Escrivá and Opus Dei

EWTN

Films and specials — on Friday at 4:30 a.m./6 p.m. and 4:30 p.m., and Saturday at 2 a.m., 4 a.m., 9:30 a.m., 1:30 p.m. and 2 p.m. — describe the life and work of the founder of the personal prelature Opus Dei.

Dan Engler writes from Santa Barbara, California.