There is a Phenomenon in the Catholic Church, that of incorrupt bodies of certain saints. The church classifies these as relics of the saints. They are uniquie because they defy the laws of nature. Some bodies are still completely incorrupt, some have begun the normal process of a deceased body while others were incorrupt for years but due to the normal processes they are now buried.
Having been echumed in September 1909, in April 1919, then in April 1925, the intact body of Bernadette is kept since August 3, 1925 in a Shrine in the chapel of the convent of St. Gildard at Nevers.
St. Bernadette 1844-1879
The face that saw the Virgin Mary 18 times
There have been many others whos bodies have not began the natural order of decay after many years since there death. Here is a list of just some of those who are incorupt.

St.John Vianney, 1786-1859

St. Catherine laboure

St. Vincent De Paul, 1580-1660

St. Francis Xavier,1500-1552

St. Margeret Mary Alacoque, 1647-1690

Blessed Anna Marie Taigi, 1769-1837

St.Clare of Assisi, 1194-1253