Don Sinclair Davis, PhD (August 4, 1942 – June 29, 2008) was an American character actor best-known for playing General Hammond in the television series "Stargate SG-1" (1997–2007), and earlier for playing Major Garland Briggs on the television series "Twin Peaks" (1990–1991).
 He was also a theater professor, painter, and United States Army captain.
Daniel Jackson, Ph.D., is a fictional character in the military science fiction franchise "Stargate", and one of the main characters of the series "Stargate SG-1."
 He is portrayed by James Spader in the 1994 film "Stargate", and by Michael Shanks in "Stargate SG-1" and other "SG-1" derived media.
 Jackson is the only "Stargate" character to appear in all of the films and series in the franchise (not including the non-canonical "Stargate Infinity"); the main character Jack O'Neill did not appear in the 2008 film "".
Stargate SG-1 (often abbreviated as SG-1) is an adventure and military science fiction television series and part of Metro-Goldwyn-Mayer's "Stargate" franchise.
 The show, created by Brad Wright and Jonathan Glassner, is based on the 1994 science fiction film "Stargate" by Dean Devlin and Roland Emmerich.
 The television series was filmed in and around the city of Vancouver, British Columbia, Canada.
 The series premiered on Showtime on July 27, 1997 and moved to the Sci Fi Channel on June 7, 2002; the final episode first aired on Sky1 on March 13, 2007.
 With 214 episodes over ten seasons, "Stargate SG-1" had surpassed "The X-Files" as the longest-running North American science fiction television series, until it was surpassed by the series "Smallville" in 2011.
Stargate: Continuum is a 2008 Canadian-American military science fiction direct-to-video film in the "Stargate" franchise.
 It is the second sequel to television series "Stargate SG-1" following "".
 It is directed by Martin Wood, director and producer of many episodes of "Stargate SG-1" and "Stargate Atlantis", written by "SG-1" and "Atlantis" creator Brad Wright, and produced by Wright and "Ark of Truth" director Robert C. Cooper.
Robert C. Cooper is a Canadian writer and producer best known for his work in the "Stargate" franchise.
 He was formerly an executive producer of "Stargate SG-1", "Stargate Atlantis" and "Stargate Universe".
 He also co-created both "Stargate Atlantis" and "Stargate Universe" with Brad Wright.
 Cooper has written and produced many episodes of "Stargate SG-1", "Stargate Atlantis" and "Stargate Universe" as well as directed a number of episodes.
The first season of the military science fiction television series "Stargate SG-1" commenced airing on the Showtime channel in the United States on July 27, 1997, concluded on the same channel on March 6, 1998, and contained 22 episodes.
 The show itself is a spin off from the 1994 hit movie, "Stargate" written by Dean Devlin and Roland Emmerich.
 Stargate SG-1 re-introduced supporting characters from the film universe, such as Jonathan "Jack" O'Neill and Daniel Jackson and included new characters such as Teal'c, George Hammond and Samantha "Sam" Carter.
 The first season was about a military-science expedition team discovering how to use the ancient device, named the Stargate, to explore the galaxy.
 However, they encountered a powerful enemy in the film named the Goa'uld, which is bent on destroying Earth and all that oppose them.
Samantha "Sam" Carter, USAF is a fictional character in the Canadian–American military science fiction "Stargate" franchise.
 Played by Amanda Tapping, she appears in all three shows in the franchise: "Stargate SG-1", "Stargate Atlantis", and "Stargate Universe".
 She was a main character in all ten seasons of "Stargate SG-1" (1997–2007).
 Following a recurring role in "Stargate Atlantis" for three seasons (2004–07), Carter became a main character in Season 4 of "Atlantis" (2007–08), and also appeared in the 2008 direct-to-DVD "SG-1" films "" and "".
 Amanda Tapping accepted a starring role in "Sanctuary" and appears in only the first and last episodes in Season 5 of "Atlantis" (2008–09).
 Carter also appears in two episodes of Season 1 of "Stargate Universe."
Season eight of "Stargate SG-1", an American-Canadian military science fiction television series, began airing on July 9, 2004 on the Sci Fi channel.
 The eighth season concluded on February 22, 2005, after 20 episodes on British Sky One, which overtook the Sci Fi Channel in mid-season.
 This was the first season of the show to have 20 episodes instead of 22, as well as the first to air concurrently with "Stargate SG-1" spinoff series "Stargate Atlantis" (the first season thereof).
 The series was originally developed by Brad Wright and Jonathan Glassner, while Brad Wright and Robert C. Cooper served as executive producers.
 Season eight regular cast members include Richard Dean Anderson, Amanda Tapping, Christopher Judge, and Michael Shanks.
 The eighth season begins with the SG-1 team trying to revive Colonel Jack O'Neill (Richard Dean Anderson) after the events of the seventh season.
 At the end of the two-episode season opener, Colonel O'Neill is promoted to General and assumes command of Stargate Command (SGC), while Major Samantha Carter (Amanda Tapping) is promoted to Lieutenant Colonel and assumes command of SG-1.
 The season arc centers on the growing threat and seemingly final defeat of the Goa'uld and the Replicators, races who were introduced in the first and third season of the show, respectively.
Lieutenant General George S. Hammond, USAF (Ret.)
 is a fictional character in the "Stargate franchise".
 Played by American actor Don S. Davis, General Hammond serves as the commander of Stargate Command (SGC) in the first seven seasons of the television series "Stargate SG-1".
 He is relieved of command in the series' season 7 finale "Lost City", but becomes head of the new Homeworld Security department at the beginning of season 8.
 Hammond's off-screen retirement is confirmed in "SG-1"' s season 10, and the character's death is mentioned in the series finale of "SG-1"' s spin-off series "Stargate Atlantis", "Enemy at the Gate".
"Enemy at the Gate" is the 100th and final episode of the science fiction television series "Stargate Atlantis".
 The episode aired on January 9, 2009 on the Sci Fi Channel in the United States, and on January 13, 2009 on Sky1 in the United Kingdom.
 Written by Joseph Mallozzi and Paul Mullie as their fifth and final script in the fifth season, "Enemy at the Gate" was produced as the nineteenth episode of the season and was directed by Andy Mikita.
 It is dedicated to Don S. Davis ("Stargate SG-1"'s George Hammond), who died from a heart attack in 2008.

Question: Enemy at the Gate was dedicated to the actor known for playing which character on Stargate SG-1?
Answer: General Hammond