It united a number of former Marxists, notably P.B. Struve (who had written the RSDRP's first programme), and the philosophers N.A. Berdyaev and S.L. Frank, with a number of former Narodniks, such as A.V. Peshekhonov, N.F. Annensky and V.A. Myakotin, and with national liberals like P.N. Miliukov who had no socialist background at all.