Varför inträffade händelserna i The Purple Wedding inte tidigare?

Jag tror inte att detta uttryckligen anges i böckerna eller tv-serierna, men min tolkning var detta:

Lady Olenna visste från sina samtal med Sansa att

Joffrey was a monster, and that she did not want Lady Margery married to such a man.

Emellertid

she still wanted Margery to become the Queen. The only way to achieve both goals was to kill Joffrey. However, if Joffrey died after the wedding, the Tyrells would be the first ones Cersei accused: she'd recognize that they got everything they wanted, and discarded her son once they were done with him.

Så den bästa lösningen var

kill Joffrey at the worst possible time for the Tyrells: right before the wedding. This way, Joffrey is eliminated without any fingers pointed their way, and Margery is in a position to be betrothed to the mild-mannered Tommen.

Spoilers för boken (jag vet inte hur TV-serien behandlar det här, så jag kan inte ta itu med det):

Olenna didn't plan the assassination by herself; it was a conspiracy of her and Littlefinger and possibly Margaery Tyrell. I don't believe that it was Olenna who chose the occasion, but Littlefinger who chose it. And he chose it because the occasion of the wedding, with its mass drunkenness and mass confusion, made it easier to blame Tyrion and spirit away Sansa. Why did Olenna go along with it? We don't know what Littlefinger said to her, but we do know he can be very persuasive.

Det här är spekulativt, men med ett bröllops natur kan många komma nära Joffrey. Detta dödar misstankar på ett stort antal människor och gör det möjligt för konspiratorer att ha trovärdig förneklighet (i värsta fall) eller att avböja skulden till en annan part (tyrion).

Det kan ha varit svårt att ordna ett annat tillfälle som skulle ha gjort det möjligt för dem att peka skulden ifrån sig själva. När allt kommer omkring skulle mordet ha gjort lite bra för Littlefinger om

Sansa was imprisoned for the assassination and beyond his reach

eller för Tyrellerna om

Lady Olenna was accused. This might even cause the Lannisters to have the wedding annulled and/or remove Tyrells from the small council.