Complex sentence: Soon after their takeover of power in Germany, the Nazi government initiated talks with the Holy See concerning the establishment of a concordat because of Catholic resistance to Nazi policies in Germany; the talks last three and half months while Hitler consolidated his hold on power.
Split into simpler sentences: Soon after their takeover of power in Germany, the Nazi government initiated talks with the Holy See concerning the establishment of a concordat. The talks lasted three and half months while Hitler consolidated his hold on power.