The most powerful of the kings of Cashel during this period was Cathal, who died in 742. The annals indicate that he held virtually equal authority with the contemporary high-kings. One of the prerogatives of the high-king was to preside over the Assembly of Taillte ("Teltown," near Navan). In 733, Cathal seems to have attempted to preside over this assembly, in the absence of the high-king Flaithbertach, who was engaged at the time in a losing struggle to preserve his own authority in the north-west. Cathal's attempt to preside over the high-king's assembly was forcibly prevented by Domhnall, king of Midhe. In 734, Cathal appears to have secured the adherence or submission of the king of Ossory in an effort to extend his power over Leinster; and a fierce battle ensued, in which the king of Ossory was killed and the king of Cashel escaped alive. In 737, a convention was held between Cathal and the high-king, Aedh Allán, at Terryglass in Ormond, and apparently an agreement was made between them securing the claim of the church of Armagh to revenue from all Ireland. In 738, Cathal again invaded Leinster and exacted hostages and a heavy contribution from the king of Naas. In view of all this, the name of Cathal was afterwards included by some southern writers in the list of monarchs of Ireland. In Leinster, a factor against peace was the ancient claim of the high-kings to tribute from the Leinster kings. The origin of this tribute, called the Bóramha or "kine-counting," is explained by two different stories. Possibly it originated in the conquest of northern Leinster. The tribute was seldom conceded but to main force. To exact it at least once in a reign was a point of honour, a test of the monarch's authority; and an invasion of Leinster for that purpose is an almost regular item in the annals under the first or second year of each high-king.