The phrase "man's best friend" has new meaning when you consider these brave canines. We highlight some of the bravest dogs in history, from a black poodle who fought in the Napoleonic Wars to the Belgian Malinois involved in the raid on Osama bin Laden's compound. Pictured is the famous statue in Edinburgh, Scotland, of Greyfriars Bobby, a terrier who guarded the grave of his owner for 14 years.

1 of 11 Balto Brown Brothers/Wikimedia Commons. Balto was the lead sled dog on the last leg of a famous, life-saving medical delivery to Nome, Alaska, in 1925. There was a serious outbreak of diphtheria in the city, and medical officials needed antitoxins to prevent the upper respiratory tract infection from spreading. The nearest doses were in Anchorage. Officials were forced to rely on dogsleds to deliver the antitoxins because the extreme cold made other modes of transport impossible. The run took seven days. By the time Balto and his team were on the road with their cargo, sled driver Gunnar Kaasen (with Balto at left) could barely see in front of him and was forced to rely on the dogs to reach Nome without his direction. Balto was celebrated as a hero upon their arrival in Nome and later with a media tour. A statue was dedicated to him in Central Park in New York City.

2 of 11 Belgian Malinois Photo: By Best dog photo/Shutterstock One of four varieties of Belgian sheep herding dogs, Belgian Malinois are highly regarded for their ability to perform in dangerous situations. Used by SWAT teams and militaries around the world, the dogs are easily trained for all sorts of tasks, including sniffing out drugs and bombs, personal protection and search-and-rescue missions. Though easily mistaken for German shepherds, these dogs have a more elegant build than their cousins, without sacrificing speed, strength or agility.

3 of 11 Laika Photo: [public domain] /Wikimedia Commons History remembers Yuri Gagarin as the first man in space in 1961, but he was preceded in 1957 by Laika, a female terrier mix who was scooped up from the streets of Moscow and rocketed into history — becoming the first animal to orbit the Earth. Launched in the Russian satellite Sputnik 2, Laika became a global celebrity as the world marveled at her bravery. Awe quickly turned to anger as it was revealed not long after the launch that the Soviets did not have a way to return Laika safely to Earth. She died after four days in the satellite due to overheating, and her remains were incinerated as Sputnik 2 re-entered Earth's atmosphere.

4 of 11 Smoky Used by permission, Copyright Wm. A. Wynne, 2011. This 4-pound Yorkshire terrier lived large. Smoky was found in the jungle of New Guinea and soon was purchased by an American soldier, Bill Wynne. Wynne trained her, according to the Yorkie Doodle Dandy website, and the tiny, 7-inch dog accompanied him for two years during World War II. While abroad, she entertained troops and earned honors for her bravery, saving Wynne's life on at least one occasion by warning him of incoming fire on a transport ship. After the war, Smoky and Wynne went home to Cleveland, Ohio, and continued to entertain veterans and the public. She is memorialized with a statue in Lakewood, Ohio.

5 of 11 Sgt. Stubby Photo: U.S. Army/Wikimedia Commons Serving with the 102nd Infantry, 26th (Yankee) Division, Sgt. Stubby was a pit bull mix who snuck his way onto the battlefields of World War I in France and became the unit's mascot. Shortly after arriving, Stubby's unit was hit with a gas attack. After that, Stubby — with his keen ears and nose — would alert his unit to incoming attacks to give the men time to put on gas masks. Stubby became an ideal search-and-rescue dog. He sniffed out a German spy, earning him a promotion to sergeant, the only dog ever to receive such a promotion through combat.

6 of 11 Hachiko Wikimedia Commons. Hachiko, an Akita Inu, is one of the most loyal dogs in history. Hachiko would meet his owner every day at Shibuya Station in Tokyo as the owner returned from work. In 1925, the owner died while at work and never returned home. Hachiko returned to the train station day after day, even escaping from new owners to await the return of his deceased owner. A statue of Hachiko now stands at Shibuya Station, and the spot where Hachiko stood for many years is marked with a set of bronze paw prints.

7 of 11 Tsunami-surviving dogs LNeilB2/YouTube/Japan TV. Dogs aren't only man's best friend, they also help one another. After an earthquake and tsunami rocked Japan in March, residents scrambled for shelter. The media was stunned by the dog who stayed by the side of an injured dog. The guard dog growled and barked at approaching humans, no doubt concerned for his canine companion's welfare. Eventually, rescuers were able to calm down the dog — enough to bring both dogs to safety.

8 of 11 Mancs Rodrigo/Wikipedia. A famous rescue dog from Hungary, Mancs (whose name means "paw") was a member of the Spider Special Rescue Team of Miskolc, Hungary. Mancs and the team traveled around the world to search for survivors after earthquakes. Mancs was known for his keen sense of smell and the clear signal he sent to rescuers to indicate if someone was alive under the rubble. A statue of Mancs (at left) was erected in Miskolc in 2004, two years before his death.

9 of 11 Moustache Wikipedia. Moustache, a black poodle, is perhaps the oddest addition to the list. Parts of his story are believed to be fictitious, but Moustache's fame spread far and wide, including a write-up in the New York Times. His most accomplished moments are said to have occurred during the Battle of Austerlitz in 1805, during which Moustache not only detected and cornered an Austrian spy (seen at left), but carried back the French flag to camp after losing a leg in an artillery blast. Moustache received a medal for his bravery and dedication.

10 of 11 Rags U.S. Army Signal Corps/Wikipedia. Rags, a mixed-breed terrier, fought alongside the U.S. 1st Infantry division in World War I. Pvt. James Donovan stumbled upon the dog while he was in Paris — initially using the dog as an excuse to avoid being arrested for being away without leave. He returned to duty, bringing along the dog as a division mascot. Rags soon became a carrier dog, delivering notes across dangerous fields to various posts. Rags and Donovan were both involved in a serious gas attack and were shipped back to the United States. Donovan died in the hospital, but Rags survived and became a celebrity around the country, eventually ascending to the rank of lieutenant colonel. He was buried with military honors in Silver Spring, Maryland.