The first Strategist Dalek of the New Dalek Paradigm was created as one of five new Dalek types by the Progenitor aboard their last surviving ship above Earth in 1941 when the last three Daleks tricked the Eleventh Doctor into allowing them to activate the Progenitor device. It personally exterminated two of the old Daleks who were deemed inferior, a disguised Ironside and its unaltered counterpart.
When the Doctor attempted to pass a Jammie Dodger as a self-destruct device for his TARDIS to threaten the Daleks, the Strategist's scan determined that no such device existed. Immediately after, the Strategist warned the Supreme of multiple projectiles approaching their ship. As the Daleks established a time corridor to escape, the Strategist reported that the time jump would commence in thirty rels. Just prior to the jump, the Strategist reported that the Oblivion Continuum was inactive. The five new Daleks escaped through a time corridor and went on to rebuild their empire. (TV: Victory of the Daleks) After branding themselves as the new Supreme Council, the five conquered Goth to build an army. The Strategist then used a Time-Space Visualiser to observe the Dalek Empire's Robomen, ordering the Scientist Dalek to create the Dalek puppets based off their designs. The many failures of the Paradigm eventually saw its five founders demoted to a token presence in the Parliament of the Daleks with its new Prime Minister becoming the leader of the Daleks. (PROSE: The Astounding Untold History of the Greatest Enemies of the Universe)
After the decision-making of the Parliament was crippled by their forgetting the Doctor, (TV: Asylum of the Daleks) the original Paradigm Daleks returned to the leadership of the Empire when the Prime Minister was driven mad upon remembering the Doctor, before perishing at the end of the Siege of Trenzalore. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)
Behind the scenes
As with its fellow new Daleks, the Strategist Dalek in Victory of the Daleks was depicted with a specially created prop. This prop was later modified to serve as the active Stone Dalek in The Big Bang.
Of the four subordinates of the original, deep-voiced Supreme Dalek, the Strategist was the only one heard to speak.