Phayap Army

Phayap Army (ทัพพายัพ RTGS: Thap Phayap or Payap, northwest) was the Thai force that invaded the Burma on May 10, 1942, during the Burma Campaign of World War II.

Order of battle of Phayap Army 1942
Phayap Army (Northern Army) - Lieutenant General Charun Ratanakun (Seriroengrit)
 * 2nd Infantry Division - Major General Luang Phairirayordejd
 * 4th Infantry Regiment (Prachinburi) which consisted of
 * 10th Infantry Battalion (Prachinburi)
 * 11th Infantry Battalion (Prachinburi)
 * 12th Infantry Battalion (Prachinburi)
 * 5th Infantry Regiment which consisted of
 * 13th Infantry Battalion
 * 14th Infantry Battalion
 * 15th Infantry Battalion
 * 12th Infantry Regiment (Phitsanuloke) which consisted of
 * 28th Infantry Battalion (Nakhon Sawan)
 * 29th Infantry Battalion (Phitsanuloke)
 * 33rd Infantry Battalion (Phitsanuloke)
 * 4th Artillery Battalion (Prachinburi)
 * 5th Artillery Battalion (Prachinburi)
 * 6th Artillery Battalion
 * Attached:
 * 5th Cavalry Battalion / Cavalry Division
 * Tank squadron / Armoured Regiment
 * 3rd Infantry Division - Major General Phin Choonhavan
 * 7th Infantry Regiment (Nakhon Ratchasima) which consisted of
 * 19th Infantry Battalion (Nakhon Ratchasima)
 * 20th Infantry Battalion (Nakhon Ratchasima)
 * 21st Infantry Battalion (Nakhon Ratchasima)
 * 8th Infantry Regiment (Surin) which consisted of
 * 17th Infantry Battalion
 * 18th Infantry Battalion
 * 52nd Infantry Battalion
 * 9th Infantry Regiment (Ubon Ratchathani) which consisted of
 * 25th Infantry Battalion (Ubon Ratchathani)
 * 26th Infantry Battalion (Ubon Ratchathani)
 * 27th Infantry Battalion (Ubon Ratchathani)
 * 7th Artillery Battalion (Nakhon Ratchasima)
 * 8th Artillery Battalion (Nakhon Ratchasima)
 * 9th Artillery Battalion
 * Motorcycle Reconnaissance Squadron
 * Tank squadron
 * 4th Infantry Division - Colonel Luang Haansongkhram
 * 3rd Infantry Regiment (Lopburi) which consisted of
 * 4th Infantry Battalion (Lopburi)
 * 6th Infantry Battalion (Lopburi)
 * 8th Infantry Battalion (Saraburi)
 * 13th Infantry Regiment (Lampang) which consisted of
 * 30th Infantry Battalion (Lampang)
 * 31st Infantry Battalion (Chiang Mai)
 * 34th Infantry Battalion (Lampang)
 * 3rd Artillery Battalion
 * 10th Artillery Battalion (Nakhon Sawan)
 * Cavalry Division - Lieutenant Colonel Thwuan Wichaikhatkha
 * 35th Cavalry Regiment which consisted of
 * 3rd Cavalry Battalion (Ubon Ratchathani)
 * 5th Cavalry Battalion (Roi Ed)
 * 46th Cavalry Regiment which consisted of
 * 4th Cavalry Battalion (Chanthaburi)
 * 6th Cavalry Battalion
 * Tank Battalion
 * 12th Independent Cavalry Regiment which consisted of
 * 1st Cavalry Battalion (Bangkok)
 * 2nd Cavalry Battalion (Prachinburi)
 * 35th Infantry Battalion (Chiang Mai)
 * 1st Engineer Battalion (Ratchaburi)
 * 2nd Engineer Battalion (Chachoengsao)
 * 3rd Engineer Battalion
 * 4th Engineer Battalion
 * 1st Artillery Battalion (Bangkok)
 * 11th Artillery Battalion
 * Phayap Army AA Battalion
 * Phayap Army Transport Battalion
 * Phayap Army Water Transport Battalion

Reorganization
During the fighting, Phayap Army has added the following units by regrouping
 * The 17th Infantry Regiment (Batterfield) which conssited of
 * 32nd Infantry Battalion (Nakhon Sawan)
 * 35th Infantry Battalion (Chiang Mai)
 * 39th Infantry Battalion (Nakhon Srithammarat)

The tough weather really a big bane to Cavalry men - to see their horses perish before the actual fighting - forcing the early dissolution of the Cavalry Division and moving the 35th Cavalry Regimen to Roy Ed and the 1st Cavalry Battalion (Royal Guard using Australian Stallons) back to BKK.

Nevertheless, RTA has created the following units to replace the cavalry units within Phayap Army:
 * 11th Heavy Machine Gun Battalion
 * 1st Machine Gun Battalion
 * 2nd Machine Gun Battalion
 * 27th Artillery Battalion
 * 29th Artillery Battalion

2nd Army
After peace in Kentung has been restored in 1943, Royal Thai Army has withdrawn some units of Phayap Army and create the 2nd Army as the reserved forces

In 1943, RTA has created The 2nd Army (Lopburi) which consisted of
 * 1st Division (Chiang Rak) which consisted of
 * 1st Infantry Regiment (Bangkok) which consisted of
 * 1st Infantry Battalion (Royal Guard) (Bangkok)
 * 3rd Infantry Battalion (Bangkok)
 * 9th Infantry Battalion (Bangkok)
 * 2nd Infantry Regiment (Bangkok) which consisted of
 * 2nd Infantry Battalion (Bangkok)
 * 7th Infantry Battalion (Bangkok)
 * 37th Infantry Battalion (Ratburi)
 * 45th Infantry Battalion (Phetburi)
 * 1st Cavalry Battalion (Moved out of Phayap Army back to Bangkok after dissolving the 12th Independent Cavalry Regiment due to the diseases which killed Australian Horses used by 1st Cavalry Battalion)
 * 1st Artillery Battalion
 * 7th Division (Lopburi) consisted of
 * 19th Infantry Regiment (Bua Chum, Chai Badan district of Lopburi) which consisted of
 * 58th Infantry Battalion (Bua Chum, Chai Badan district of Lopburi)
 * 59th Infantry Battalion (Bua Chum, Chai Badan district of Lopburi)
 * 20th Infantry Regiment (Lom Sak district of Phechabun)
 * 60th Infantry Battalion (Lom Sak district of Phechabun)
 * 61st Infantry Battalion (Lom Sak district of Phechabun)
 * 21st Infantry Regiment (Wang Chomphoo in Lom Kao district of Phechabun)
 * 62nd Infantry Battalion (Wang Chomphoo in Lom Kao district of Phechabun)
 * 63rd Infantry Battalion (Wang Chomphoo in Lom Kao district of Phechabun)
 * 64th Infantry Battalion (Wang Chomphoo in Lom Kao district of Phechabun)
 * 12th Infantry Regiment (Moved out of Phayap Army back to Nakhon Sawan) consisted of
 * 28th Infantry Battalion (Nakhon Sawan)
 * 65th Infantry Battalion (Nakhon Sawan)
 * 6th Inf. Reg (Move out of Phayap Army back to Phitsanuloke) consisted of
 * 29th Inf. Bat. (Phitsanuloke) - separated from the 12th Inf. Reg
 * 66th Inf. Bat. (Nakhon Sawan)
 * 67th Inf. Bat. (Tak)

37th Division
In 1944, Royal Thai Army has created the following units to help and train Serithai (Free Thai Movement) without being hunted down by Imperial Japanese Army
 * 37th Division (Nakhon Ratchasima which consisted of
 * 107th Infantry Regiment (Nakhon Ratchasima)
 * 35th Cavalry Regiment (Roi Ed) - move from Phayap Army - consisted of
 * 3rd Cavalry Battalion (Ubon Ratchathani)
 * 5th Cavalry Battalion (Roi Ed)
 * the 108th Infantry Regiment (Udon Thani - Nakhon Phanom)
 * the 9th Infantry Regiment (Ubon Ratchathani) - move from Phayap Army
 * 25th Infantry Battalion (Ubon Ratchathani)
 * 26th Infantry Battalion (Ubon Ratchathani)
 * 27th Infantry Battalion (Ubon Ratchathani)

Demobilization
After the peace declaration on 16 August 1945, the following units of Phayap Army along with War time units have been dissolved and demobilized:

30 October 1945: The following units have been effectively dissolved and demobilized 13 November 1945: The following units have been effectively dissolved and demobilized
 * 11th Heavy Machine Gun Battalion
 * 1st Machine Gun Battalion
 * 2nd Machine Gun Battalion
 * 27th Artillery Battalion
 * 29th Artillery Battalion
 * Phayap Army HQ
 * 2nd Army
 * 7th Division
 * 37th Division
 * 18th Mixed Brigade at 4 States of Melayu
 * 20th Infantry Regiment
 * 107th Infantry Regiment.
 * 4th Cavalry Battalion
 * 6th Artillery Battalion
 * 14th Artillery Battalion
 * 32nd Infantry Battalion (Nakhon Sawan)
 * 33rd Infantry Battalion (Reserved Forces)
 * 34th Infantry Battalion (Lampang)
 * 35th Infantry Battalion (Chiang Mai)
 * 54th Infantry Battalion
 * 56th Infantry Battalion
 * 40th Infantry Battalion (Trang)
 * 41st Infantry Battalion (Songkla)

Postwar Reorganization
The Postwar reorganization of Royal Thai Army in 1946:
 * 1st Army Circle (Bangkok) consisted of
 * the 1st Infantry Regiment (Royal Guard) (Bangkok) - which consisted of
 * 1st Infantry Battalion (Royal Guard) (Bangkok)
 * 3rd Infantry Battalion (Royal Guard) ((Bangkok)
 * 9th Infantry Battalion (Royal Guard) (Bangkok)
 * the 11th Infantry Regiment (Bangkok) - Renamed from the 2nd Infantry Regiment - which consisted of
 * 2nd Infantry Battalion (Bangkok)
 * 7th Infantry Battalion (Bangkok)
 * 37th Infantry Battalion (Ratchaburi)
 * 45th Infantry Battalion (Phetburi)
 * 2nd Army Circle (Prachinburi) consisted of
 * 2nd Infantry Regiment (Lopburi) - Renamed from the 3rd Infantry Regiment consisted of
 * 4th Infantry Battalion
 * 6th Infantry Battalion
 * 8th Infantry Battalion
 * 12th Infantry Regiment (Prachinburi) - Renamed from the 4th Infantry Regiment consisted of
 * 10th Infantry Battalion
 * 11th Infantry Battalion
 * 12th Infantry Battalion
 * 3rd Army Circle consisted of
 * the 3rd Infantry Regiment (Nakhon Ratchasima) - Renamed from the 7th Infantry Regiment consisted of
 * 19th Infantry Battalion
 * 20th Infantry Battalion
 * 21st Infantry Battalion
 * 13th Infantry Regiment (Ubon Ratchathani) - Renamed from the 9th Infantry Regiment consisted of
 * 25th Infantry Battalion (Ubon Ratchathani)
 * 26th Infantry Battalion (Ubon Ratchathani)
 * 27th Infantry Battalion (Ubon Ratchathani)
 * 4th Army Circle consisted of
 * 4th Infantry Regiment (Nakhon Sawan) which consisted of
 * 28th Infantry Battalion (Nakhon Sawan)
 * 29th Infantry Battalion (Phitsanuloke)
 * 30th Infantry Battalion (Lampang)
 * 31st Infantry Battalion (Chiang Mai)
 * 5th Army Circle (Nakhon Srithammat) which consisted of
 * 5th Infantry Battalion (Hat Yai - Songkla)
 * 38th Infantry Battalion (Chumporn)
 * 39th Infantry Battalion (Nakhon Srithammarat)
 * 42nd Infantry Battalion (Khok Pho - Patani)

Air Force
Chief-of-the-Air-Staff - Group Captain Khun Ronnaphakasd

90th Combined Wing - ?
 * 41st Squadron
 * Curtiss Hawk III
 * 42nd Squadron
 * Curtiss Hawk III
 * 32nd Squadron
 * Vought Corsair V-93s


 * 11th Squadron
 * Mitsubishi Ki-30
 * 12th Squadron
 * 17 Mitsubishi Ki-30


 * 61st Squadron
 * Martin 139WS
 * 62nd Squadron
 * Mitsubishi Ki-21-I