Per https://www.ourfamtree.org/pedigree.php/Walter-de-Greene/106582, his parents are Thomas Greene (1343-) and Margery Mablethorpe (1345-). The parents of Thomas are Henry Greene (1320-) and Catherine Drayton (1324-) who are the parents of ancestor Agnes\Margaret Green. That means Walter is the nephew of ancestor Agnes\Margaret and their ancestors are DOUBLE ANCESTORS. Since they fall into different generations on the family tree, thus, are kept in separate family lines.

This line goes back 8 generations into the 1100's.

Historical
1371: Turkey, Bulgaria - Serbs defeated by Ottoman Turks at Maritsa River (Bulgaria)
1372-1375: England, France - Hundred Years War resumes when the French fleet defeats the British fleet off La Rochelle y France, the French are helped by a powerful fleet from Castile, the Truce of Bruges is signed on June 27, 1375 limiting British presence in France to Calia, Brest, Bordeaux and Bayonne
1381: England - The Peasants Revolt led by Wat Tyler create anarchy throughout England burning a number of public buildings and beheading the archbishop of Canterbury, King Richard puts down the riot and Tyler is killed
1381: Italy - War of Chioggia, Venetian fleet under Vittoria Pisano defeat the Genoans, It begins the golden age of Venice
1384: Uzbekistan - Timur captures Herat, Sistan, Rayy, and Il-Khanid (the capital of Sultaniyeh)
1385: Portugal - Battle of Aljubarrota (central Portugal), Portugese under King John I defeat the Crown of Castile under King John I and his allies, the victory makes Portugal an Independent country
1389: Turkey - Turkish army under Sultan Murad I defeats Serbs under Prince Lazar at Kossovo Field (meaning "field of the black birds"), bringing Turkish rule to the area which lasts until the Balkan War of 1913, just before the battle, a Serb posing as a deserter brought before Sultan Murad produces a dagger and stabs the Sultan to death, he is Immediately killed, as is Serb leader Lazar who is captured in the battle
1392: China - Yi Songgye, with the aid of the Ming rulers of China, seize the Korean throne from the Koryo dynasty, the Yi dynasty lasts until 1910
1395: Mongolia - Timur sacks Sarai Berke, ending central control of the Mongol Golden Horde
1396: Turkey, Hungary - Ottomans defeat Hungarians at Nicopol
1397: Sweden, Norway, Denmark - Magaret, Queen of Sweden, conquers Denmark and Norway then forms the Kalamar League, a union of all three countries
1398: Mongolia, India - Timur sacks Delhi, causing demise of the Delhi Sultinate, founded back in 1192
1400: Indonesia - Paramesvara founds the Kingdom of Malacca on the Malay peninsular (Indonesia), It soon becomes the leading maritime power in South East Asia
1400: Mongolia, Syria, Russia, Georgia, Iraq - Mongol conqueror Timur Invades Syria after devastating Georgia and Russia, the next year he lays waste to Aleppo, Damascus and Baghdad and the year after that e defeats the Ottoman sultan at the Battle of Angora
1402: Mongolia, Turkey - Timur captures Ottoman Turk Sultan Beyazid I at Angora
1405: Mongolia - Mongol leader Timur dies suddenly while preparing to attack Ming China, the Mongol Empire rapidly falls apart, Timur is buried at Samarkand (Uzbekistan)
1410: Poland, Germany - Battle of Tannenberg, Poles and Lithuanians defeat German Knights, the Peace of Thorn is signed but the Poles failed to gain access to the sea
1412: France - Joan of Arc born in Domremy, France
1415: England, France - Henry V of England defeats French army at Agincourt, Pas de Calais, France, 7,000 French killed, 500 English killed
1415: England - Battle of Agincourt, the English destroy the French, British archers under the command of Henry V were the key to victory, shattering the feudal system
1415: Portugal, Morroco - Portuguese explorer and prince, Henry the Navigator captures Ceuta (Morocco) from the Marind dynasty beginning Portuguese colonization of Africa
1420: China - Upon the death of the Ming emperor, the sSecond Ming Emperor moves the capital of China from Nanking to Peking
1420: England, France - Treaty of Troyes, France (under Philippe) signs a treaty with England (under Henry V) making Henry the king of both countries
1423: England, France, Scotland - Battle of Cravant, after a year of fighting, the English, under the command of John Plantagent, defeat the combined forces of France and Scotland
1424: England, Scotland - After being held in captivity since age 11, the English free James I King of Scotland age 29 after the Earl of Somerset pays 10,000 marks in ransom as a dowry for his daughter Jane, Jane and James are married and James is crowned King of Scotland
1424: France, Italy - Charles VIII King of France Invades Italy and forces Naples to surrender, then Alexander VI organizes the Holy League and forces Charles out of Italy
1428: England, France - War between France and England continues despite various agreements, in 1428 the English beseige Orleans and Joan of Arc, a young girl from Lorrain, is visited by Saint Michael saying that she will have visions and hear voices from God, that convince the French dauphin to provide her with a small army that liberates Orleans, this gives the French new confidence in their conflict with England
1431: France - Joan of Arc enters Comiegne outside Paris and is taken prisoner, held in a tower in Rouen and Charles VII makes no effort to assist her, in 1431 Joan is turned over to the former bishop of the of Beauvais Pierre Cauchon on the assurance she would be convicted of treason against God and is burned at the stake on May 30
1431: Thailand, Cambodia - The Thais capture Angkor, the capital of the Khmer, the Khmer Empire move their capital to the present site of the Cambodian capital of Phnom Penh
1435: England, France - Duke Philip of Burgundy, weary of his alliance with the English, signs a peace treaty with Charles VI which recognizes Charles as the one king of France who in turn promises to punish the murders of Philip's father, however, the English do not accept the peace treaty and warfare continues. Charles and Philip fight together and liberate Paris, a truce between Britain and France lasts thirteen years
1438: Peru - Inca Dynasty in Peru (it lasts until 1553) begins, Its founder is said to have been Pachacutec who rapidly expands the empire
1439: Italy, Turkey - Treaty between Roman Catholic Church and Eastern Orthodox Church
1444: Turkey - Battle of Varna, Murad the Ottoman sultan attacks on Its Belgrade but is repeled, encouraged by victory, the Christians, whose goal has been to drive the Ottomans from Europe, declare a new Crusade led by Hunyadi
1450: Germany - Johannes Gutenberg Invents the printing press which revolutionizes communication and education, allows the development of newspapers and reasonably priced books, the first product printed is the Guttenberg Bible
1453: England, France - Battle of Castillon, French king Charles VI becomes the first king to maintain a standing army and attempts to reclaim Normandy defeat the English led by Talbot thus ending the Hundred Years War when the English surrender last outpost in Aquitaine
1453: Turkey - The ten century old Byzantine Empire ends when Muhammad II of Turkey captures Constantinople by hauling seventy small ships across land along with cannon that breached the wall of Constantinople
1454: Italy - Treaty of Lodi ends hostilities between Venice, Milan and Florence, the treaty was reached due to the efforts of Pope Nicholas V
1455: England - War of the Roses begins, a civil war between the houses of Lancaster and York and is limited to English nobility, the first battle was the Battle of St. Albans which took place near London, the Yorkist defeat the Royalist forces
1456: Portugal, Cape Verde Islands - Alivse da Cadamosto, employed by Henry the Navigator, discovers the Cape Verde Islands off the African coast near Dakar, the Islands are soon settled by the Portuguese who began to use It for the slave trade
1460: England - Battle of Wakefield, Queen Margaret of Anjou defeats and kills Richard Duke of York
1461: England - Battle of Towton Moors, in the War of Roses, the Royalist who wore red roses to battle are defeated by the Yorkist wearing white roses, Edward is crowned Edward IV King of England
1462: Turkey - Ottoman Sultan Muhammad II defeats Vlad IV ("Vlad the Impaler") of Walachia
1471: England - Battle of Tewkesbury, in the War of the Roses, Edward IV marries Elizabeth Woodville and is soon ousted by Earl of Warwick so that King Henry can return, Warwick is killed in the Battle of Barnet and Henry was returned to prison and Immediately killed and Margaret, his wife, continues the struggle but at the Battle of Tewkesbury her son is killed and she is captured
1471: Vietnam - Le Thanh-ton begins the Kingdom of Annam by capturing Vijaya the capital of the Cham (Vietnam)
1472: Turkey - Ivan III the Great marries the neice of the last Byzantine Emperor, It Increases Ivans prestige and helps him unify the various Russian principalities
1475: England, France - Treaty of Picquinty England's Edward IV Invaded France in support of the Burgundians. Edward was bought off by a payment and the promise of an annual allowance by Louus XI under the terms of the Treaty of Picquinty