[3] Prclamation's dam Shamarra was an unraced mare bred by the Aga Khan and bought as a five-year-old for IR£55,000 by Cathal Ryan's Stacumny Stud.
[7] On his first appearance as a three-year-old, Proclamation contested the Group Two Dante Stakes (a major trial for The Derby) over ten and a half furlongs at York Racecourse in May when he was ridden for the first time by Frankie Dettori.
He was restrained by Dettori in the early running before accelerating into the lead approaching the final furlong and drawing away to win "comfortbly" by three lengths from the David Elsworth-trained favourite Tucker.
Ridden by Johnny Murtagh, he started the 7/1 third favourite behind the Michael Stoute-trained Home Affairs and the Sandy Lane Stakes winner Camacho.
On 27 July, Proclamation was matched against older horses for the first time in the Group One Sussex Stakes over one mile at Goodwood where he was ridden by Mick Kinane.
[11] On the day after the race, Noseda reported that the horse had indicated his wellbeing by "screaming for his breakfast" that morning: he suggested the Queen Elizabeth II Stakes and the Breeders' Cup Mile as likely targets.
[12] In September, Proclamation was dropped to six furlongs for the Group One William Hill Sprint Cup at Haydock Park and was made the 6/4 favourite against sixteen opponents.
For the 2006 season, Proclamation entered the ownership of Sheikh Mohammed's Godolphin organisation and was transferred to the stable of Saeed bin Suroor.