Similarities can certainly be seen in the two Old English poems Beowulf and Judith, by unknown authors. One similarity can be seen in the fact that both characters are portrayed as heroes of groups of people who are being crushed by their enemies.
In Judith, which is based on the Apocryphal Book of Judith, the heroine Judith rescues her people, the Israelites, from the attacking Assyrians and Babylonians. After conquering the Egyptians and Assyrians, Nebuchadnezzar II, King of Babylon, next invaded Jerusalem in 605 BC, accompanied by his newly conquered Assyrian troops ("Siege of Jerusalem (597 BC)"). To rescue her people, Judith connives a way to assassinate Holofernes, attributed to be Nebuchadnezzar's Assyrian general. Knowing that Holofernes was prone to drunkenness, Judith gains access into his tent on a night she knows he is completely drunk. While Holofernes is in a drunken stupor, Judith succeeds in overpowering and decapitating him, forcing the Babylonian and Assyrian troops to retreat since they are left without a leader.
Similarly, in Beowulf, Hrothgar, King of the Danes, and his people are being terrorized by the monster Grendel. Hrothgar began building up his army in Herot, and the noise of the training woke up Grendel, who then set out killing and terrorizing the soldiers. Beowulf, leader and later king of the Geats, a Northern Germanic tribe in what is now Sweden, promises Hrothgar he will kill Grendel. Beowulf feels it is his duty to help Hrothgar because Beowulf's father, Ecgtheow, while living, was a friend of Hrothgar's. To prove his valor, Beowulf promises not to fight Grendel using any shield, armor, or weapons. Instead, in hand-to-hand combat, Beowulf tears off Grendel's arm and shoulder, wounds Grendel dies of during the night.
Other similarities can be seen in the fact that both poems are considered moral tales. Beowulf had no real need to assist Hrothgar other than the need to show friendship and even honor his deceased father's friendship. Beowulf's willingness to sacrifice himself for the mere sake of friendship shows us just how much the story emanates Christian morality and virtues. Likewise, Judith risks her own life, thereby sacrificing herself out of love for her people. Since both Christianity and Judaism are Abrahamic religions, we can see how both stories reflect the Abrahamic morals of love and self-sacrifice.
For the purposes of research, the dates of the work are particularly fascinating to look at. The date Judith was written is not known for certain. Some attribute the poem to the English poet Caedmon, placing it having been written in 680 A.D., in the 7th century, while others place it having been written between the 8th and 10th centuries. Similarly, Beowulf is placed as having been written in England between the 8th and 11th centuries. Hence, both were presumably written by English poets in approximately the same relative medieval time period. What's also interesting is that both were found in the same manuscript known as the Nowell Codex, dated between 975 and 1025 A.D. In addition, one poem is about a man, while the other is, obviously, about a woman. One might question the medieval author's intent for placing two heroic poems about both genders side by side.
As a research question, one might ask, what do both poems show about the attributes valued in both men and women during the medieval period?