The ARIES recovery algorithm has had a significant impact on current thinking on transaction processing, logging and recovery. In this paper, we present the C-ARIES algorithm, which extends the original algorithm with the capability to perform transaction aborts and crash recovery in a highly concurrent manner. Concurrency is achieved by performing transaction aborts and the Redo and Undo recovery phases on a page-by-page basis. An additional benefit of C-ARIES is that the database system can commence normal processing at the end of the Analysis phase, rather than waiting for the recovery process to complete.