This contribution deals with cationic ruthenium allenylidene complexes bearing a large variety of differently substituted allenylidene ligands attached to the metal. We discuss their synthesis and how the identity of the ER n substituent influences their spectroscopic and electrochemical properties. It is shown, how data from different spectroscopies and electrochemical half-wave potentials relate to each others and provide a consistent picture of the bonding within these systems. Experimental results are compared to those from quantum mechanical studies.