In the years that followed it would get several expansions, the most recent of which being the 2008 stand-alone release called Soulstorm, which built on Dark Crusades’ campaign layer but made it across an entire star system.
It’s certainly the best Warhammer 40K game, although as far as ‘old school’ Relic goes Company of Heroes is considered the better game, in many respects.
Released in 2006, the original Dawn of War is probably one of the best RTS games in existence.