Rebellions continued to occur in Wales sporadically. These included revolts in 1287-8, and more seriously, in 1294 under Madog ap Llywelyn, a distant relative of Llywelyn ap Gruffudd and in 1316-1318 by Llywelyn Bren, Lord of Senghenydd. In the 1370s, Owain Lawgoch the last representative in the male line of the ruling house of Gwynedd planned two invasions of Wales with French support. In 1400, a Welsh nobleman, Owain Glyndŵr , led the most serious revolt against English rule. None of these rebellions succeeded and by the Laws in Wales Acts 1535-1542 Wales was effectively incorporated into the Kingdom of England.
Question: How many years did Llywelyn Bren lead the revolts?
Answer: 2