British King Crown Badge (c. WWII)
 
The King's Crown (KC), also referred to as the Imperial Crown or Tudor Crown. Shown here in its simplest form as rank insignia.
 
The King's Crown replaced the Victorian  Crown in 1901, and was superseded itself by the Queen's Crown (QC) in 1953. It is worth noting that as a general rule (there are exceptions) KC insignia would be produced in the period 1901-54, but the wearing of KC insignia could and did persist for some units into the QC period.