Using both a pulsed and a narrow-band cw dye laser, laser-induced fluorescence excitation spectra of N2(B, upsilon = 1 0) were observed on the N2(B 3PI(g) <-- A 3SIGMA(u)+ transition from the metastable N2(A) component of a molecular beam. Lifetime measurements were made for some of the B, upsilon = 10 rotational/fine structure levels, including one which was recently shown to exhibit very specific kinetic effects due to a perturbation by the N2(A’ 5SIGMA(g)+) state [Ch. Ottinger, L. G. Smirnova and A. F. Vilesov, J. Chem. Phys. 100, 4848 (1994)). The perturbation manifested itself in the present work by a significantly longer lifetime of the 3PI2e(12) level relative to other B, 10 levels, as well as by line shifts. The S/O interaction matrix element is obtained to be 0.35 cm-1. From the required very close accidental coincidence between well-identified levels in the B and A’ states the term energy of the latter could be precisely determined as T(e)(A’ 5SIGMA(g)+)=75 990.0 cm-1. This is the first measurement of this value, and the result is congruent-to 440 cm-1 lower than was predicted by ab initio calculations.