co - king relationship to monarch          crowned co - kingship ceased            reason              monarch
0  robert (ii)                     son  30 december 987       24 october 996  became sole king           hugh capet
1  hugh magnus                     son     19 june 1017    17 september 1025              died  robert ii of france
2    henry (i)                     son      14 may 1027         20 july 1031  became sole king  robert ii of france
3   philip (i)                     son      23 may 1059        4 august 1060  became sole king    henry i of france
4       philip                     son    14 april 1129      13 october 1131              died   louis vi of france
5  louis (vii)                     son  25 october 1131        1 august 1137  became sole king   louis vi of france

Table as JSON:
{"co - king":{"0":"robert (ii)","1":"hugh magnus","2":"henry (i)","3":"philip (i)","4":"philip","5":"louis (vii)"},"relationship to monarch":{"0":"son","1":"son","2":"son","3":"son","4":"son","5":"son"},"crowned":{"0":"30 december 987","1":"19 june 1017","2":"14 may 1027","3":"23 may 1059","4":"14 april 1129","5":"25 october 1131"},"co - kingship ceased":{"0":"24 october 996","1":"17 september 1025","2":"20 july 1031","3":"4 august 1060","4":"13 october 1131","5":"1 august 1137"},"reason":{"0":"became sole king","1":"died","2":"became sole king","3":"became sole king","4":"died","5":"became sole king"},"monarch":{"0":"hugh capet","1":"robert ii of france","2":"robert ii of france","3":"henry i of france","4":"louis vi of france","5":"louis vi of france"}}