“King” (8 p.m., History): Martin Luther King Jr. was assassinated when he was 39. Now,

“King” (8 p.m., History): Martin Luther King Jr. was assassinated when he was 39. Now, four decades later, the anniversary of his death is marked by a documentary that explores his life and legacy. “King” revisits signal moments from his fight for civil rights: the bus boycott in Montgomery; the march in Selma; his incarceration in Birmingham; the march on Washington and his speech where he declared unforgettably “I have a dream.” Among those interviewed for the special are former President Clinton, Harry Belafonte, Chuck D, Forest Whitaker and Andrew Young, who marvels that King “always saw himself as inadequate. He always felt like he wasn’t doing enough.” Program host Tom Brokaw also speaks with Martin Luther King III, who suggests that his father would be “quite disappointed” at the lack of progress in race relations the last 40 years.

“Monk” (8 p.m., NBC): The cable hit, “Monk,” debuts on NBC tonight with an episode that has our nervous detective making friends with a happy-go-lucky guy played by Andy Richter. They hit it off, but Monk’s new BFF may not be what he seems to be. The episode airs just before “Psych” makes its NBC debut.

“Egypt’s Ten Greatest Discoveries” (8 p.m., Discovery Channel): Egypt’s innovations — construction marvels such as the pyramids, as well as mathematics, language and art — have reached across the centuries to influence modern life. This special includes expert analysis of Egypt’s achievements and their effects. Another new program, “Why Ancient Egypt Fell” (10 p.m.), looks at how global warming and other factors might have led to the destruction of the empire.

“America’s Port” (10 p.m., National Geographic Channel): The port of Los Angeles is one of the world’s most important trade gateways. The nation’s largest container port, it keeps a work force of 16,000 busy handling hundreds of tons of consumer goods every day — including 40 percent of all goods imported into the United States. But along with the unceasing work of handling cargo, there is also a constant threat from contraband and terrorism. Customs officials and the port’s own police force play important roles, too. In charge of it all is the executive director, Geraldine Knatz, the first female boss in the port’s centurylong history. “America’s Port” is an eight-part documentary series that follows its round-the-clock operations and introduces viewers to some of the people who keep it operating. It premieres 10 p.m. Sunday on National Geographic Channel, then, for the second hour, moves into its regular time period, 10 p.m. Monday.