Temporal Knowledge Graphs (Temporal KGs) extend regular Knowledge Graphs by providing temporal scopes (e.g., start and end times) on each edge in the KG. While Question Answering over KG (KGQA) has received some attention from the research community, QA over Temporal KGs (Temporal KGQA) is a relatively unexplored area. Lack of broadcoverage datasets has been another factor limiting progress in this area. We address this challenge by presenting CRONQUESTIONS, the largest known Temporal KGQA dataset, clearly stratified into buckets of structural complexity. CRONQUESTIONS expands the only known previous dataset by a factor of 340×. We find that various state-of-the-art KGQA methods fall far short of the desired performance on this new dataset. In response, we also propose CRONKGQA, a transformerbased solution that exploits recent advances in Temporal KG embeddings, and achieves performance superior to all baselines, with an increase of 120% in accuracy over the next best performing method. Through extensive experiments, we give detailed insights into the workings of CRONKGQA, as well as situations where significant further improvements appear possible. In addition to the dataset, we have released our code as well.1. The underlying KG is a Temporal KG.2. The answer is either an entity or time duration. 3. Complex temporal reasoning might be needed. KG Embeddings are low-dimensional dense vector representations of entities and relations in a KG. Several methods have been proposed in the literature to embed KGs (Bordes et al. 2013, Trouillon et al. 2016, Vashishth et al. 2020). These embeddings were originally proposed for the task of KG completion i.e., predicting missing edges in the KG, since most real world KGs are incomplete. Recently, however, they have also been applied to the task of KGQA where they have been shown to increase performance the settings of both of complete and incomplete KGs (Saxena et al. 2020;).