input: After the First Punic war, the massive war debt suffered by Carthage led them to attempt to expand their control over the Iberian peninsula. Hamilcar Barca began this conquest from his base at Cadiz by conquering the Tartessian Guadalquivir river region, which was rich in silver. After Hamilcar's death, his son-in-law Hasdrubal continued his incursions into Iberia, founding the colony of Qart Hadasht (modern Cartagena) and extending his influence all the way to the southern bank of the river Ebro. After Hasdrubal's assassination in 221 BC, Hannibal assumed command of the Carthaginian forces and spent two years completing the conquest of the Iberians south of the Ebro. In his first campaign, Hannibal defeated the Olcades, the Vaccaei and the Carpetani expanding his control over the river Tagus region. Hannibal then laid siege to Roman ally of Saguntum and this led to the beginning of the Second Punic War. The Iberian theater was a key battleground during this war and many Iberian and Celtiberian warriors fought for both Rome and Carthage, though most tribes sided with Carthage.  Rome sent Gnaeus and Publius Cornelius Scipio to conquer Iberia from Carthage. Gnaeus subsequently defeated the Iberian Ilergetes tribe north of the Ebro who were allied with Carthage, conquered the Iberian oppidum of Tarraco and defeated the Carthaginian fleet. After the arrival of Publius Scipio, Tarraco was fortified and, by 211 BC, the Scipio brothers had overrun the Carthaginian and allied forces south of the Ebro. However, during this campaign, Publius Scipio was killed in battle and Gnaeus died in the retreat. The tide turned with the arrival of Publius Cornelius Scipio Africanus in 210 BC. Scipio attacked and conquered Carthago Nova and defeated the army of Hasdrubal Barca at the Battle of Baecula (209-208). The war dragged on with Carthage sending more reinforcements until the Battle of Ilipa (modern Alcala del Rio in Sevilla province), which was a decisive victory for Publius Scipio Africanus. The Carthaginians retreated to Gades, and Publius Scipio gained control over the entire south of the peninsula. After this victory, the Ilergetes and other Iberian tribes revolted and it was only after this revolt that the Romans conquered the rest of the Carthaginian territories in southern Spain.  After the Carthaginian defeat, the Iberian territories were divided into two major provinces, Hispania Ulterior and Hispania Citerior. In 197 BC, the Iberian tribes revolted once again in the H. Citerior province. After securing these regions, Rome invaded and conquered Lusitania and Celtiberia. The Romans fought a long and drawn out campaign for the conquest of Lusitania. Wars and campaigns in the northern regions of the Iberian peninsula would continue until 16 BC, when the final rebellions of the Cantabrian Wars were defeated.

Answer this question "What groups of people fought against each other?"
output: many Iberian and Celtiberian warriors fought for both Rome and Carthage,

Question: Ludendorff was born on 9 April 1865 in Kruszewnia near Posen, Province of Posen, Kingdom of Prussia (now Poznan County, Poland), the third of six children of August Wilhelm Ludendorff (1833-1905). His father was descended from Pomeranian merchants who had achieved the prestigious status of Junker. Erich's mother, Klara Jeanette Henriette von Tempelhoff (1840-1914), was the daughter of the noble but impoverished Friedrich August Napoleon von Tempelhoff (1804-1868) and his wife Jeannette Wilhelmine von Dziembowska (1816-1854), who came from a Germanized Polish landed family on the side of her father Stephan von Dziembowski (1779-1859). Through Dziembowski's wife Johanna Wilhelmine von Unruh (1793-1862), Erich was a remote descendant of the Counts of Donhoff, the Dukes of Duchy of Liegnitz and Duchy of Brieg and the Marquesses and Electors of Brandenburg.

In the West in 1916 the Germans attacked unsuccessfully at Verdun and soon were reeling under British and French blows along the Somme. Ludendorff's friends at OHL, led by Max Bauer, lobbied for him relentlessly. The balance was tipped when Romania entered the war, thrusting into Hungary. Falkenhayn was replaced as Chief of the General Staff by Field Marshal Hindenburg on 29 August 1916. Ludendorff was his chief of staff as first Quartermaster general, with the stipulation that he would have joint responsibility. He was promoted to General of the Infantry. Chancellor Bethmann-Hollweg warned the War Cabinet: "You don't know Ludendorff, who is only great at a time of success. If things go badly he loses his nerve." Their first concern was the sizable Romanian Army, so troops sent from the Western Front checked Romanian and Russian incursions into Hungary. Then Romania was invaded from the south by German, Austro-Hungarian, Bulgarian, and Ottoman troops commanded by August von Mackensen and from the north by a German and Austro-Hungarian army commanded by Falkenhayn. Bucharest fell in December 1916. According to Mackensen, Ludendorff's distant management consisted of "floods of telegrams, as superfluous as they were offensive."  When sure that the Romanians would be defeated OHL moved west, retaining the previous staff except for the operations officer, blamed for Verdun. They toured the Western Front meeting --and evaluating-- commanders, learning about their problems and soliciting their opinions. At each meeting Ludendorff did most of the commander's talking. There would be no further attacks at Verdun and the Somme would be defended by revised tactics that exposed fewer men to British shells. A new backup defensive line would be built, like the one they had constructed in the east. The Allies called the new fortifications the Hindenburg Line. The German goal was victory, which they defined as a Germany with extended borders that could be more easily defended in the next war.  Hindenburg was given titular command over all of the forces of the Central Powers. Ludendorff's hand was everywhere. Every day he was on the telephone with the staffs of their armies and the Army was deluged with "Ludendorff's paper barrage"  of orders, instructions and demands for information. His finger extended into every aspect of the German war effort. He issued the two daily communiques, and often met with the newspaper and newsreel reporters. Before long the public idolized him as their Army's brain.

Using a quote from the above article, answer the following question: Were there other countries involved?
HHHHHH
Answer:
Romania was invaded from the south by German, Austro-Hungarian, Bulgarian, and Ottoman troops