The prominence of the Ulster Unionist Council quickly grew thanks to the strong unionist sentiment in Ulster. From 1910, it became the dominant force and focus of resistance in the Irish unionist community. The JCUAI was effectively controlled by Ulstermen, while the IUA's leadership remained largely in the hands of Southern Unionists. This led to the unionist movement gradually becoming 'Ulsterised' from 1910, which marginalised many more moderate unionists in the south. Even so, in 1913, as the Third Home Rule Bill passed through Parliament, the Alliance appears to have become increasingly popular in the south and records show an increase in membership.