This dissertation investigates long-distance backwards pronominal dependencies (backwards anaphora or cataphora) and constraints on such dependencies from the viewpoint of language development and real-time language processing. Based on the findings from a comprehension experiment with Russian-speaking children and on real-time sentence processing data from English and Russian adults I argue for a position that distinguishes structural and non-structural constraints on backwards anaphora. I show that unlike their non-syntactic counterparts, structural constraints on coreference, in particular Principle C of the Binding Theory (Chomsky 1981), are active at the earliest stage of language development and of real-time processing. In language acquisition, the results of a truth-value judgment task with 3-6 year old Russian-speaking children reveal a striking developmental asymmetry between Principle C, a cross-linguistically consistent syntactic constraint on coreference, and a Russian-specific discourse constraint on coreference. Whereas Principle C is respected by children already at the age of three, the Russian-specific (discourse) constraint is not operative in child language until the age of five. These findings present a challenge for input-driven accounts of language acquisition and are most naturally explained in theories that admit the existence of innately specified principles that underlie linguistic representations. In real-time processing, the findings from a series of self-paced reading experiments on English and Russian show that in backwards anaphora contexts the parser initiates an active search for an antecedent for the pronoun which is limited to positions that are not subject to structural constraints on coreference, e.g. Principle C. This grammatically constrained active search mechanism associated observed in the processing of backwards anaphora is similar to the mechanism found in the processing of another type of a long-distance dependency, the wh-dependency. I suggest that the early application of structural constraints on long-distance dependencies is due to reasons of parsing efficiency rather than due to their architectural priority, as such constraints aid to restrict the search space of possible representations to be built by the parser. A computational parsing algorithm is developed that combines the constrained active search mechanism with a strict incremental left-to-right structure building procedure.