Loading a WW1 British 15 in (381 mm) howitzer

A howitzer or hauwitzer is a type of field artillery. Howitzers are used to fire explosive shells at ground targets up to about 25-30 kilometres away. The name comes from Czech houfnice, denoting a 15th century cannon used by Hussites. Howitzers are distinguished from other types of cannon artillery by their trajectory in that they can shoot both high- and low-angle, in other words both above and below 45 degrees elevation. In addition to this quality, the barrel of a howitzer is below 30 calibers, i.e. the length of the barrel is less than 30 times as long as the diameter of the bore, whereas a cannon must either be able to only fire low-angle, or high-angle as well and have a caliber of 30 or over. Typical 155 mm cannons, or gun howitzers as they are often called, usually have a barrel length of 39, 45 or 52 calibers.

Modern howitzers are commonly either self-propelled or towed. During World War II, a 75 mm "pack" howitzer was in common use. The 75 mm howitzer could be disassembled into several main components and carried by mule through very difficult terrain. Howitzers of such small caliber have generally been abandoned in favor of larger guns with greater capabilities. Modern howitzers fire 105 to 155 millimetre diameter shells at a maximum rate of approximately 10 per minute.

Small howitzers can be towed by a utility vehicle such as a humvee or airlifted by helicopter. Most are towed by five-ton or larger trucks. Recent developments favour self-propelled artillery because of its shrapnel protection. The G6 from South Africa is a self propelled howitzer that was developed around the ordnance of the G5 howitzer. It is currently the most powerful self-propelled equipment on a wheeled chassis

Howitzers used by the United States armed forces include:

• M102 howitzer 105 mm, towed
• M198 howitzer 155 mm, towed
• M109 howitzer 155 mm, self-propelled
• M110 howitzer 8 inch (203 mm), self-propelled

The Dutch, German, Italian and Greek armies have been using or will be using PzH 2000 howitzer (155 mm, self-propelled) shortly.

The Big Bertha was a large, 42 centimeter howitzer used in the German push of 1914. The gun was based on a similar 42 centimeter gun manufactured for a short while by Krupp for the German military.

That similar, older 42 centimeter gun was based almost completely on a gun designed by Louis Gathmann in the late 1800s. Louis was known as the inventor of the "Big Berthas" up through his death in June of 1917. Even the New York Times labeled Louis Gathmann as the inventor.

In November 1990 British customs officers seized parts of a 1000 mm howitzer destined for the Iraq Project Babylon "supergun", which, had it been built, would have been the largest gun ever constructed.

The term "howitzer" is also used metaphorically for a brutal, merciless attack. Example: New York Times MARCH 28, 2004, "Most recently, Ms. Hughes was an advocate of the howitzer treatment of Mr. Clarke, the former counterterrorism chief who was attacked by the White House as politically motivated and dishonest."

See also

• SSPH1 Singapore's 155 mm Automated SP gun
• FH-2000 Singapore's 155 mm 52 calibre Towed Gun
• XM2001 Crusader
• 25 Pounder Short Mark 1
• M107 (projectile)