A few trips into the neighboring countries,--first of all his participation in the expedition of the students to Upsala, in 1856, immediately thereupon a prolonged residence in Copenhagen,--brought his poetic talents to maturity. He had already begun his little drama "De Nygifte" (The Newly Married Couple), but had laid it aside with a keen sense of the inadequacy of his powers, not to resume work on it until ten years later. In brief lyric poems of the genuine folk-song character, he had calmed his creative impulse without satisfying it. He now wrote the firstling of his dramatic muse, "Mellem Slagene" (Between the Battles), an earnest little play in one act, that treats of an episode from the Norwegian civil war of the early Middle Ages, and whose terse, ragged prose style, which formed the sharpest contrast to the sonorous, verbose iambics of the Danish dramas of the Oehlenschläger school, inaugurated a new form of the Northern style. The play was rejected by Heiberg, at that time director of the royal theatre at Copenhagen, was first produced on the stage in Christiania, and was not printed until some time afterward. How far Björnson and the entire later poetic literature have progressed on the path thus broken, can be best observed by witnessing to-day a theatrical performance of this little drama, which on its first appearance repelled, because of the supposed wildness of its materials and the harshness of their treatment, and which now actually seems to us quite idyllic and by far too sentimental.