Lines 1-4 introduce the poem's title character, "Drummer Hodge," after he's already died. This first stanza is set in the present tense; the second, which adds a hint of Hodge's backstory, will be in the past tense, and the third will look ahead to the future.
Here, an unnamed "They" dumps Hodge's lifeless body into an improvised grave. They bury Hodge "Uncoffined" (without a coffin), "just as [they] found" him on the "veldt," or open country of southern Africa. His grave is unmarked, except that it's set atop the geographical "landmark" of a "kopje-crest": a small hill that disrupts ("breaks") the flatness of the surrounding landscape.
"Kopje," like "veldt," is a term particularly associated with the landscape of southern Africa, so these words help establish the poem's setting. Both come from the southern African language called Afrikaans, which combines Dutch with elements of German and the Khoisan languages native to the region. Both words, then, are artifacts of European colonialism, particularly Dutch settlement in what is now South Africa. They would have struck Thomas Hardy's main audience (UK readers) as distinctively "foreign," and would have had topical significance as well. Hardy wrote the poem in 1899, the year the British Empire and the Boer Republics (states founded by Dutch colonists) began waging the Second Boer War in southern Africa.
Readers of the time would have immediately recognized that Hardy was alluding to this war and that the "Drummer Hodge" character was supposed to be a British casualty of that war. Military drummers were typically young men—often too young to fight as regular soldiers—who played field music as their armies marched into battle. Meanwhile, "Hodge" was a kind of stock name for an English country dweller or farm laborer.
Just in these first few lines, then, the third-person speaker casts Hodge as an unlucky fish out of water, a young English army recruit who has died under unknown circumstances far from home. He's also a somewhat generic figure, buried without a funeral or headstone in the midst of a vast landscape. It's not even clear who's burying him—comrades, enemies, or civilians.
Already, the poem is starting to offer an implied commentary, portraying war as a heartless force that doesn't care about individual identities. (In that way, it may be like the natural landscape surrounding Hodge's body.)