Under the defence review announced in July 1957, the number of battalions in the brigade was reduced to four in 1958: the East Yorkshire Regiment and the West Yorkshire Regiment were amalgamated into the Prince of Wales's Own Regiment of Yorkshire, while the Royal Northumberland Fusiliers were transferred to the newly formed Fusilier Brigade.
In July 1957, a defence review caused the brigade's battalions to be reduced from four to four: the East Yorkshire Regiment and the West Yorkshire Regiment were merged into the Prince of Wales's Own Regiment of Yorkshire, while the Royal Northumberland Fusiliers were transferred to the newly formed Fusilier Brigade.