DUP was the last deputy mayor of Derry City Council. The post has a long history. A provost was appointed in the initial city charter of 1604. In 1613, this post was replaced with that of mayor, with John Rowley being the first to serve. The City charter of 1665 which provided: During much of its history, it has been held by Unionists (largely due to the practice of gerrymandering), but in later years, the majority of mayors were nationalists, reflecting the make-up of the city's population and council. In the 1990s the post was alternated between nationalist and unionist councillors regardless of the size of the vote of either side. From 1921 until 1969, the mayor was automatically entitled to a seat in the Senate of Northern Ireland. Political makeup From 1973 elections to Derry City Council were conducted under the single transferable vote system, and are normally held every four years. Elections took place in five electoral areas, the boundaries of which were changed for the 1985 local elections, when the number of councillors was increased from 27 to its final figure of 30. The last elections to Derry City Council were held on 5 May 2011, with the city's voters electing thirty councillors across five electoral areas. The election resulted in all four parties returning the same number of seats they had won in the 2005 elections, with the SDLP remaining the largest party, only two seats short of overall control of the council. The results are summarised below: †Unionist parties fought the 1973 elections in an electoral pact, as United Loyalists. Of the 9 councillors elected under this label, 5 contested the 1977 elections for the UUP, 1 for the DUP, 1 for the Vanguard Unionist Progressive Party, 1 as a Loyalist, while one councillor did not stand again. Local politics Prior to 1969, elections to the Londonderry county borough council were based on block voting. The electoral wards had been drawn and redrawn to ensure a unionist majority on the council even though more voters supported nationalist and republican parties. With local government reorganisation in 1973, the old county borough was merged with the surrounding Londonderry Rural District to form the new local government district of Londonderry. In addition, a system of STV was introduced which has resulted in a majority of councillors from nationalist and republican parties being elected, with the SDLP consistently being