When viewers meet Cersei in the first episode, she had just reluctantly made the journey from King's Landing to Winterfell with her (now late) husband, King Robert Baratheon. At the time, she was playing the part of dutiful wife. However, her choice of clothing in House Lannister's colors of red and gold hinted at what relationships were truly important to her.
After successfully plotting the death of Robert and ensuring the ascension of Joffrey — her oldest son with her twin brother Jaime — to the Iron Throne, she adopted ever more regal outfits that signified her growing power.
Cersei's most recent ensemble — the militant black gown she wore to be crowned as Queen of the Seven Kingdoms in the season six finale — demonstrated her ruthlessness in the wake of the death of her last surviving child. "Black was the obvious choice,” costume designer Michele Clapton told Vanity Fair. "Yes, it is for mourning her children, her father . . . but it’s more than that. To me, it represents a deadness inside her—the overwhelming desire for power at any cost. The multi-layered effect created by mounting the leather onto silver brocade gives a more complex feeling, implying that nothing achieved is ever simple.”
See the full gallery of Cersei's costumes above.