Question: What form of armored heavy cavalry used in ancient warfare did Grivpanvar fought?
Context: Light cavalry, often called Light Horse, comprises lightly armed and lightly armoured troops mounted on horses, as opposed to heavy cavalry, where the riders (and sometimes the horses) are heavily armored.  The missions of the light cavalry were primarily reconnaissance, screening, skirmishing, raiding, and most importantly, communications, and were usually armed with spears, swords, bows and later carbines. A cataphract was a form of armored heavy cavalry used in ancient warfare by a number of peoples in Western Eurasia and the Eurasian Steppe. The National cavalry (Polish: "Kawaleria narodowa" ) was a branch of Polish–Lithuanian cavalry in the Polish armed forces in the last quarter of the 18th century.  Formed as a merger of previously-existing units of Polish Hussars and pancerni that were still in service after the Confederation of Bar.  In 1777 the Sejm new regulations converted all units of heavy cavalry and medium cavalry and reformed them into a line cavalry, roughly similar to later uhlans popular in Europe in the 19th century.  Existing dragoon and Front or Vanguard Regiments were outside this reform The National Cavalry had a very short history of 20 years, and some units stationed in the eastern Polish–Lithuanian Commonwealth were forcibly incorporated into the Russian cavalry following the Second Partition of Poland, and the remainder was disbanded together with the rest of Polish–Lithuanian armed forces after the final partition in 1795.  The Sejm's 1777 decision was rather late effort to modernize Polish–Lithuanian cavalry, along the much earlier trend of evolution of European cavalry towards more modern organization of the cavalry regiments into more mobile formations.  The most modern part of the reform was the establishment of some very modern battle dress uniforms for these cavalrymen, and in turn this uniform of the National Cavalry inspired numerous similar uniforms and employment of 'Polish lance' in the rest of Europe, notably the Austrian, Prussian, Russian cavalry, and later of the French cavalry of the Napoleonic Wars. The Chevalier Guard Regiment (Russian: Кавалергардский полк ) was a Russian heavy cavalry guard regiment, created in 1800 by the reformation of the Chevalier Guard corps, itself created in 1764 by Catherine the Great.  As other Russian heavy cavalry guard regiments (the Life-Guards Horse Regiment, His Majesty's Life-Guards Cuirassier Regiment, and Her Majesty's Life-Guards Cuirassier Regiment), the Chevalier Guards were equipped as cuirassiers (with some differences in uniform and equipment from army cuirassiers and other guard cuirassier regiments). Duncan B. Campbell is a scholar of Greek and Roman warfare.  He published his first paper in 1984, as an undergraduate at Glasgow University (Scotland), and produced a complete re-assessment of Roman siegecraft for his PhD.  Besides academic articles, he has written several popular books about ancient warfare, chiefly siegecraft, published by Osprey Publishing.  He is a regular contributor to "Ancient Warfare" magazine and a frequent reviewer for "Bryn Mawr Classical Review". The 1st Royal Saxon Guards Heavy Cavalry ("Garde-Reiter-Regiment (1.  Schweres Regiment)") was a heavy cavalry of the Royal Saxon Army.  Established in 1680 as a cuirassiers unit, the regiment fought in the Battle of Vienna (1683), the Nine Years' War, the War of the Spanish Succession, the Silesian Wars, the Napoleonic Wars, the Austro-Prussian War, the Franco-Prussian War and World War I.  The regiment was disbanded in 1919. The Grivpanvar (literally: neck-guard wearer), were an elite late Parthian and Sassanian division who fought as heavy knights or Cataphract cavalry.  According to Roman sources, the Grivpanvar had the ability to impale two men on the long, heavy spears that they carried.  Historical evidence suggests that the heavily armoured Parthian grivpanvar were at least partially influenced by the military of the Central Asian steppes, who in turn had inherited their armoured cavalry traditions from the Massagetae and the late Achaemenid Persians. The Great Stirrup Controversy is the academic debate about the Stirrup Thesis, the theory that feudalism in Europe was largely the result of the introduction of the stirrup to cavalry.  It relates to the hypothesis suggested by Lynn Townsend White, Jr. in his 1962 book, "Medieval Technology and Social Change."  White believed that the stirrup enabled heavy cavalry and shock combat, which in turn prompted the Carolingian dynasty of the 8th and 9th centuries to organize their territory into a vassalage system, in which these mounted warriors were rewarded with land grants for their service.  White's book has proved very influential, but he has also been accused of speculation, oversimplification, and ignoring contradictory evidence on the subject.  Other scholars have debated whether the stirrup actually provided the impetus for this social change, or if the rise of heavy cavalry was a result of political changes in Medieval Europe. Armand Lebrun de la Houssaye (20 October 1768–19 June 1848) led a cavalry division during the First French Empire of Napoleon.  He joined the army of the First French Republic in 1791 and fought at Kaiserslautern in 1793.  He was appointed to lead a hussar regiment the following year.  Promoted to general officer in 1804, he led a heavy cavalry brigade at Austerlitz, Eylau, and Heilsberg and a division at Friedland.  Transferred to Spain, he commanded a dragoon division under Marshal Nicolas Soult at Corunna, Braga, First and Second Porto, and Arzobispo in 1809.  In 1812 he led a cavalry division in the III Cavalry Corps during the French invasion of Russia where he was badly wounded at Borodino.  While recovering in the hospital, he was captured by the Russians and held until the peace in 1814.  Lahoussaye is one of the names inscribed under the Arc de Triomphe on Column 6. The pattern 1796 Heavy Cavalry Sword was the sword used by the British heavy cavalry (Lifeguards, Royal Horse Guards, Dragoon Guards and Dragoons), and King's German Legion Dragoons, through most of the period of the Revolutionary and Napoleonic Wars.  It played an especially notable role, in the hands of British cavalrymen, at the battles of Salamanca and Waterloo.  The pattern was adopted by Sweden and was used by some Portuguese cavalry.
Answer: Cataphract