The last appearance of Old Nan in the show. The actress Margaret John passed away on 2 February 2011, two months prior to the release of the first season. Although the character makes more appearances in the books, the showrunners decided not to re-cast the role out of respect for John. It is therefore implied in the show that she died of old age, one of the few characters in the series to do so.
Doreah says she has seen a man who can change his face like a man changes his clothes. This is a reference to the Faceless Men, the assassin guild from Braavos.
To date, the only episode of the series in which every credited main cast member appears.
When Viserys is reciting the names of the dragons whose skulls were in the throne room, he mentions Vermithrax. Vermithrax Pejorative is the name of the dragon in Dragonslayer (1981). GOT author George R.R. Martin once stated that Vermithrax was the best film dragon of all time.
Tyrion says that nothing would ruin his supper more than hearing a song about his father Tywin's victory over the Mad King at King's Landing. This refers to the sack of King's Landing, the final battle in Robert's rebellion against the Mad King. The reason that Tyrion responds in disgust is that it wasn't a victorious battle, but an honorless act of treason and slaughter: Tywin, former Hand of the Mad King, had entered the city claiming to have come to the Mad King's final aid. In actuality, he had switched sides and ordered his army to unleash a wave of rape, pillaging and slaughter at the defenseless population of the city instead. Tywin also had the royal family and their entire entourage butchered in an effort to show his loyalty to Robert. The immense general hatred towards the Targaryens as well as Tywin's considerable political and monetary power prevented him from ever having to answer for these crimes. This, coupled with Jaime breaking his vow by killing the Mad King, explains why House Lannister remains one of the most hated families in Westeros; yet, because of their money and power, they are begrudgingly tolerated.