The 2 stone-carving pics are from a Jin Dynasty (1115-1234 AD) tomb showing an important figure flanked by his flag-bearer and sword-bearer. (The Jin people were a nomadic race living in northern China at that time, and who were the distant ancestors of the Qing Dynasty Manchus.)
In this case, the sword-bearer bears a heavy 2-handed sword with a ring-pommel attached.
This type of sword is what I believe to be a direct copy and descendent of the Song Dynasty zhanmadaoor horse-chopping sword, with a handle vs blade ratio of 1:3 and a total length of more than 1.2 meters.
Developed in 1072 AD, the zhanmadao was designed to enable Song infantry troops to cut through heavily armoured cavalry riders and horses. One key characteristic and tactic was to select the strongest and most courageous infantry soldiers to form into a special vanguard unit. When they confronted an enemy cavalry charge, they were trained to bend low and use the zhanmadao to strike/chop at the legs of those horses of the enemy.
This tactic was successfully used by the famous Song General Yue Fei, who had armed his soldiers with an identical or similar weapon known as the "mazhadao"; they went on to decimate the formidable heavy cavalry of the Jin Army in one major battle, prompting the defeated Jin general to exclaim that it was the first time in his combat experience where he had witnessed his heavy cavalry tactics fail.
The Song Chinese had also used the zhanmadao against enemy infantry during siege defense along city walls, in built-up areas.
Dedicated manufacturing facilities were setup to produce this weapon, which was long, stout and massive to defeat heavy armour.
The excavated sword shown here is what I believe to be the 2-handed Song Dynasty zhanmadao, excavated in China, and identified as from the Song Dynasty. The cutting edge of the excavated sword in the photo is facing down and this weapon's shape or profile does not have any relation to the swords of the Han and Tang Dynasties.
The weapon continued to be in use during the Ming Dynasty by soldiers manning the northern border to deal with Mongol cavalry; it was also distributed to the garrison troops of various provinces. During the Qing, it was also the standard equipment of the Green Standard Army (which composed mainly of ethnic Chinese soldiers).
See also my webpage on Illustrations of Qing regulation swords.
Song Dynasty Buddhist painting of the single-handed dao (called the "shoudao") issued to the Song military forces and most commonly used in conjunction with a shield.
Note the rendered martensite differentially heat-treated edge that extends beyond the cutting edge to the clipped top portion of the blade. The blade is also drawn with a disc-shaped guard and a tunkou (metal collar at the forte).
One form of quality control at the time for manufacturing these weapons was to select 20 to 30 out of every batch of a hundred, and to use these to cut through armour plate or copper coins so as to verify their quality. There is one example reportedly in the collection of the Chinese Military History Museum in Beijing. This blade profile / shape could be regarded as the ancestor of the two-handed "Dadaos" used by Nationalist and Red Army troops in WW2.
Click on the pic to view jians, the other weapon used by the Song military alongside the dao.
The various types of polearms and the "shoudao" rendered in the Song military encyclopaedia "wu jing zong yao"; the "shoudao" is rendered on the extreme right.
13th century Chinese Imperial Court painting of Yuan Dynasty Emperor Kublai Khan's Mongol bodyguard with his Turko-Mongol saber (encased within an animal fur-skin scabbard cover, and partially covered by his archery bow-case), strapped to his waist.
This type of saber was used by Mongol cavalry in the Yuan army and was the ancestor of the Ming and Qing dynasties' willow leaf and goosequill sabers (liuyedao and yanmaodao).
Originating from Central Asia around the 8th century, these sabers were widely used by the Turkic peoples of the Central Asian region and by the Mongols. It was to become the ancestor of the saber styles of the Arab/Islamic world, Persia, India and Eastern Europe as well, spreading to these regions as a consequence of Mongol-initated wars, conquests and rule.
A drawing of the typical Turko-Mongol saber used in the 13th-15th centuries
Descendent of the Turko-Mongol saber: the magnificent gold-inlaid saber made for Ottoman Turkey's Sultan Suleiman, the Magnificent, who lived 1495-1566. This saber also exhibits a ridged cross-section and is currently in the collection of Topkapi Sarayi Museum,Istanbul,Turkey.
Descendent of the Turko-Mongol saber: Imperial Guards guarding the Ming Dynasty Emperor Jiajing (1522-1567, who is not shown here), with their willow leaf sabers (liuyedao) unsheathed.